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Reference
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## Release

     gmic : GREYC's Magic Image Converter (May 27 2010, 11:24:49).

            Version 1.3.5.1, Copyright (C) 2008-2010, David Tschumperle
            (http://gmic.sourceforge.net)

## Usage

     gmic [item1 [arg1_1,arg1_2,..]] .. [itemN [argN_1,argN_2,..]]

     'gmic' is an open-source interpreter of the G'MIC language, a script-based programming
      language dedicated to the design of image processing pipelines. It can be used to
      convert, manipulate, and visualize datasets composed of one or several 1d/2d/3d
      multi-spectral images.

     The G'MIC language is quite minimalist. It is entirely defined by the following rules :

### ** Overall context :

      - At a global scale, G'MIC manages three lists of numbered items, stored in computer memory :
        _ One list of pixel-based images, each representing 1d/2d/3d scalar or multi-spectral data.
           This is actually the most important and significant dataset in G'MIC and we will focus
           on it in the followings.
        _ One list of text strings (named 'global stack'), used to store and manage global variables
           in G'MIC pipelines and custom commands.
        _ One list of display windows, which are useful objects to manage real-time animations or
           to handle user interactions.
      - The first item of any list has indice '0' and is denoted by [0].
      - Negative indices are treated in a cyclic way (i.e. [-1] stands for the last item of
         a list, [-2] the penultimate one, and so on..). Thus, in a list of 4 items, notations
         [1] and [-3] both refer to the second item.
      - The G'MIC language defines a set of commands and substitution mechanisms to create
         pipelines for managing these lists of data in a flexible way.
      - Created pipelines can then become a part of the G'MIC language, through the definition of
        user-defined custom commands.

### ** Image definition and terminology :

      - In G'MIC, an image is always stored as a 4d array of scalar-valued pixels, whose dimensions
         are respectively denoted by :
        _ 'width', for the number of image columns (size along the 'x'-axis).
        _ 'height', for the number of image lines (size along the 'y'-axis).
        _ 'depth', for the number of image slices (size along the 'z'-axis).
            The depth is equal to 1 for usual 2d color images.
        _ 'spectrum', for the number of image channels (size along the 'c'-axis).
            The spectrum is equal respectively to 3 and 4 for RGB and RGBA color images.
      - There are no limitations on the number of image slices or channels G'MIC can handle
         except the amount of available memory.
      - The width, height and depth of an image are considered as 'spatial' dimensions, while
         the spectrum has a 'spectral' meaning. Thus, a 4d image in G'MIC should always be
         regarded as a 3d dataset of multi-spectral voxels.
      - All pixel values of all images of the list have the same datatype. It can be one of :
        _ 'bool' : Value range is [0=false, 1=true].
        _ 'uchar' : Stands for 'unsigned char'. Value range is [0,255].
            This type of pixel coding is commonly used in image file formats to store
            classical 8-bits/channels RGB[A] color images.
        _ 'char' : Value range is [-128,127].
        _ 'ushort' : Stands for 'unsigned short'. Value range is [0,65535].
            This type of pixel coding is commonly used in image file formats to store
            classical 16-bits/channels RGB[A] color images.
        - 'short' : Value range is [-32768,32767].
        _ 'uint' : Stands for 'unsigned int'. Value range is [0,2^32-1] (32 bits integers).
        _ 'int' : Value range is [-2^31,2^31-1] (32 bits signed integers).
        _ 'float' : This type of coding is able to store pixels as 32 bits float-valued numbers.
            This is the default datatype considered in G'MIC to perform image processing operations.
        _ 'double' : This type of coding is able to store pixels as 64 bits float-valued numbers.
      - Considering pixel datatypes different than 'float' is generally useless, except to force
         the input/output of image data to be done in a prescribed binary format. Hence, most G'MIC
         commands are available only for the default 'float' pixel datatype.

### ** Items and processing pipeline :

      - In G'MIC, an image processing pipeline is described as a sequence of items separated by
         spaces ' '. Such items are interpreted and executed from the left to the right.
         For instance, the expression 'input.jpg -blur 3,0 -sharpen 10 -r 200%,200% -o output.jpg'
         defines a valid sequence of 9 G'MIC items.
      - G'MIC items are text strings that stand either for a command, command arguments, a filename
         or a special input string.
      - When invoking 'gmic' from the command-line, any word following the executable name is
         considered as one specified G'MIC item.
      - Escape characters '\' and double quotes '"' can be used (as usual) to define items
         containing spaces, or any other character sequences.

### ** Input data items :

      - If a specified G'MIC item appears to be a filename, the corresponding image data are loaded
         and inserted at the end of the image list.
      - Special filenames '-' and '-.ext' stand for the standard input/output streams, optionally
         forced to be in a specific 'ext' file format (e.g. '-.jpg' or '-.png').
      - The following special input strings can be used as G'MIC items in order to create and
         insert new images with prescribed values, at the end of the image list :
        _ '[indice]' or '[indice]xN' : Insert 1 or N copies of the existing image [indice].
        _ 'width[%],_height[%],_depth[%],_spectrum[%],_values' :
           Insert a new image with specified size and values (adding '%' to a dimension means
           'percentage of the size along the same axis, taken from the last available image').
           Any specified dimension can be also replaced by '[indice]', and is then replaced by
           the size along the same axis of the existing specified image [indice].
           'values' can be either a sequence of numbers separated by commas ',', or a mathematical
           expression, as e.g. in the input item '256,256,1,3,if(c==0,x,if(c==1,y,255))' which
           creates a 256x256 RGB color image with a spatial shading on the red and green channels.
        _ '(v1,v2,..)' : Create a new image containing specified prescribed values. Value separators
            inside parentheses can be ',' (column separator), ';' (line separator),
            '/' (slice separator) or '^' (channel separator). For instance, expression
            '(1,2,3;4,5,6;7,8,9)' creates a 3x3 matrix (scalar image), with values from 1 to 9.

### ** Command items and subsets :

      - A G'MIC item starting by '-' designates a command, most of the time. Mainly, commands
        perform image processing operations on one or several available image(s) of the list.
      - Usual commands may have two equivalent names (regular and short). For instance,
         command names '-resize' and '-r' refer to the same processing action.
      - A G'MIC command may have mandatory or optional arguments. Command arguments must be
         specified in the item next to the command name. Commas ',' are used to separate multiple
         arguments, if any required.
      - The execution of a G'MIC command may be restricted only to a subset of the image list, by
         appending '[subset]' to the command name. Several combinations are possible, such as :
        _ '-com[0,1,3]'        : Apply command only on images [0],[1] and [3].
        _ '-com[3-5]'          : Apply command only on images [3] to [5] (i.e, [3],[4] and [5]).
        _ '-com[50%-100%]'     : Apply command only on the second half of the image list.
        _ '-com[0,-4--1]'      : Apply command only on the first image, and the four latest ones.
        _ '-com[0-9:3]'        : Apply command only on images [0] to [9], with a step of 3
                                  (i.e. [0], [3], [6] and [9]).
        _ '-com[0--1:2]'       : Apply command only on images of the list with even indices.
        _ '-com[0,2-4,50%--1]' : Apply command on images [0],[2],[3],[4] and on the second half
                                  of the image list.
        _ '-com[^0,1]'         : Apply command on all images of the list except the two first ones.
      - G'MIC commands invoked without '[subset]' are applied by default on all images of the list.
      - A G'MIC command starting with '--' instead of '-' does not act 'in-place' but inserts its
         result as one or several new images, at the end of the image list.

### ** Input/output properties :

      - When dealing with color images, G'MIC reads, writes and displays data using the usual
         RGB color space.
      - G'MIC is able to manage 3d objects that may be read or generated by some commands. These
         objects are stored as regular one-column scalar images containing the object data, in the
         following order { header, sizes, vertices, primitives, colors, opacities }.
         This kind of 3d object representation can be processed or saved as any other regular image.
      - G'MIC is able to read/write most of the classical image file formats, including :
        _ 2d grayscale/color files : .png, .jpeg, .gif, .pnm, .tif, .bmp, ..
        _ 3d volumetric files : .dcm, .hdr, .nii, .pan, .inr, ..
        _ Image sequences : .mpeg, .avi, .mov, .ogg, .flv, ..
        _ Generic ascii or binary data files : .cimg, .cimgz, .dlm, .asc, .pfm, .raw, .txt, .h.
        _ 3d object files : .off.
      - Classical image file formats may be not always adapted to store 3d multi-spectral datasets,
        resulting in possible loss of pixel informations. Use the .cimg file format (or .cimgz,
        its compressed version) to ensure that all data are nicely handled during file operations.
      - Options for specific file formats :
        _ For video files : Only sub-frames of the image sequence may be loaded, using the input
           expression 'video.ext,[first_frame[%][,last_frame[%][,step]]]'.
           Output framerate and quality can be also set by using the output expression
           'file.mpg,25,1024' (here, for a 25 fps and 1024k bitrate).
        _ For .raw binary files : Image dimensions must be specified, using the input expression
           'file.raw,width[,height[,depth[,dim]]]]'.
        _ For .yuv files : Image dimensions must be specified, and only sub-frames of the image
           sequence may be loaded, using the input expression
          'file.yuv,width,height[,first_frame[,last_frame[,step]]]'.
        _ For .jpeg files : The output quality may be specified (in %), using the output expression
           'file.jpg,30' (here, to get a 30% quality output).
        _ Filenames with extension '.gmic' are read as G'MIC custom command files.
      - Note that some formats or options may be not supported by your current version of 'gmic',
         depending on how compilation flags have been set for your build of the G'MIC interpreter.

### ** Substitution rules :

      - In G'MIC items, some expressions starting by '@' are substituted before being interpreted.
         Use these expressions to get the current state of the interpreter environment :
        _ '@#' is substituted by the current number of images in the list.
        _ '@%' is substituted by the pid of the current process.
        _ '@*' is substituted by the current number of items in the global stack.
        _ '@{*}' or '@{*,subset}' are substituted by the content of the stack, or a subset of it.
           If specified subset refers to multiple stack items, they appear separated by commas ','.
        _ '@>' and '@<' are equivalent, and are both substituted by the number of nested
           'repeat-done' loops that are currently running.
        _ '@{>}' or '@{>,subset}' are substituted by the indice values (or a subset of them) of the
           currently running 'repeat-done' loops, expressed in the ascending order, from 0 to N-1.
           If specified subset refers to multiple loop indices, they appear separated by commas ','.
        _ '@{<}' or '@{<,subset}' do the same but in descending order, from N-1 to 0.
        _ '@indice' or '@{indice,feature}' are substituted by the list of pixel values of the image
           [indice], or by a specific feature (or subset) of it. Requested 'feature' can be one of
           the followings :
             . 'w' : image width (number of image columns).
             . 'h' : image height (number of image lines).
             . 'd' : image depth (number of image slices).
             . 's' : image spectrum (number of image channels).
             . 'r' : image shared state (1, if the pixel buffer is shared, 0 else).
             . 'n' : image name (or filename, if image has been read from a file).
             . 'b' : image basename (i.e. filename without the folder path nor extension).
             . 'x' : image extension (i.e last characters after the last '.' in the filename).
             . 'f' : image folder name.
             . '#' : number of image values (i.e. width x height x depth x spectrum).
             . '+' : sum of all pixel values.
             . '-' : difference of all pixel values.
             . '*' : product of all pixel values.
             . '/' : quotient of all pixel values.
             . 'm' : minimum pixel value.
             . 'M' : maximum pixel value.
             . 'a' : average pixel value.
             . 'v' : variance of pixel values.
             . 't' : text string built from the image values, regarded as ascii codes.
             . 'c' : (x,y,z,c) coordinates of the minimum value.
             . 'C' : (x,y,z,c) coordinates of the maximum value.
             . '(x,_y,_z,_c,_borders)' : pixel value at coordinates (x,y,z,c), with specified
                border conditions { 0=dirichlet | 1=neumann | 2=cyclic }.
             . Any other feature is considered as a specified subset of image values. For instance,
                expression '@{-1,0-50%}' is substituted by the sequence of numerical values coming
                from the first half of the last image data, separated by commas ','.
        _ '@!' is substituted by the visibility state of the instant display window [0]
           (can be equal to { 0=closed | 1=visible }).
        _ '@{!,feature}' or '@{!indice,feature}' is substituted by a specific feature of the
           instant display window [0] (or [indice], if specified). The requested 'feature' can be
           one of the followings :
             . 'w' : display width (i.e. width of the display area managed by the window).
             . 'h' : display height (i.e. height of the display area managed by the window).
             . 'd' : window width (i.e. width of the window widget).
             . 'e' : window height (i.e. height of the window widget).
             . 'u' : screen width (actually independent on the window size).
             .' v' : screen height (actually independent on the window size).
             . 'x' : X-coordinate of the mouse position (or -1, if outside the display area).
             . 'y' : Y-coordinate of the mouse position (or -1, if outside the display area).
             . 'b' : state of the mouse buttons { 1=left-state | 2=right-state | 4=middle-state }.
             . 'o' : state of the mouse wheel.
             . 'k' : decimal code of the pressed key if any, else 0.
             . 'n' : current normalization type of the instant display.
             . 'c' : boolean (0 or 1) telling if the instant display has been closed recently.
             . 'r' : boolean telling if the instant display has been resized recently.
             . 'm' : boolean telling if the instant display has been moved recently.
             . Any other feature stands for a keycode name in capital letter, and is substituted by
                a boolean describing the current key state { 0=pressed | 1=released }.
      - Expressions '~ind' or '~{ind}' are shortcuts for '@{*,ind}' where 'ind' is an integer.
         Use them to get the string value of one particular numbered item from the global stack.
      - Any other expression inside braces (as in '{expression}') is considered as a mathematical
         expression, and is evaluated. If an expression is non evaluable, it is substituted by
         the sequence of ascii codes that composes the specified string, separated by commas ','.
         For instance, item '{3+2}' is substituted by '5', and item '{foo}' by '102,111,111'.
      - The last image of the list (if any) is always associated to evaluations of '{expressions}',
         e.g. G'MIC sequence '256,128 -fill {w}' will create a 256x128 image filled with value 256.
      - Item substitution is never done in double-quoted items. One must break double quotes if
        substitution is needed, as eg. in "3+8 kg = "{3+8}" kg".
      - Equally, one can disable the substitution mechanism outside double-quoted items, by escaping
          the '@','{','}' and '~' characters, e.g. as in '\{3+4\}\ doesn't evaluate'.

### ** Mathematical expressions :

      - G'MIC has an embedded mathematical parser. It is used to evaluate formulas in '{}'
         expressions as well as in commands that may take formulas as arguments (e.g. '-fill').
      - When used in commands, a formula is evaluated for each pixel of the selected images.
      - The parser understands the following set of functions, operators and variables :
        _ Usual operators : || (logical or), && (logical and), | (bitwise or), & (bitwise and),
           !=, ==, <=, >=, <, >, << (left bitwise shift), >> (right bitwise shift), -, +, *, /,
           % (modulo), ^ (power), ! (logical not), ~ (bitwise not).
        _ Usual functions : sin(), cos(), tan(), asin(), acos(), atan(), sinh(), cosh(), tanh(),
           log10(), log(), exp(), sign(), abs(), atan2(), round(), narg(), isval(), isnan(),
           isinf(), isbool(), rol() (left bit rotation), ror() (right bit rotation), min(), max(),
           sinc().
           Function 'atan2()' is the version of atan() that takes two arguments 'y,x', as in C/C++.
           Function 'narg()' returns the number of specified arguments.
           Functions 'min()' and 'max()' can be called with a variable number of arguments.
           Functions 'isval()', 'isnan()', 'isinf()', 'isbool()' can be used to test the type of
           a given number or expression.
        _ These special variable names are pre-defined. They cannot be overloaded :
             . 'w' : width of the associated image, if any (else 0).
             . 'h' : height of the associated image, if any (else 0).
             . 'd' : depth of the associated image, if any (else 0).
             . 's' : spectrum of the associated image, if any (else 0).
             . 'x' : current processed column of the associated image, if any (else 0).
             . 'y' : current processed line of the associated image, if any (else 0).
             . 'z' : current processed slice of the associated image, if any (else 0).
             . 'c' : current processed channel of the associated image, if any (else 0).
             . 'i' : current processed pixel value (i.e. value located at (x,y,z,c)) of the
                associated image, if any (else 0).
             . 'im','iM','ia','iv' : Respectively the minimum, maximum, average values and variance
                of the associated image, if any (else 0).
             . 'xm','ym','zm','cm' : The pixel coordinates of the minimum value in the associated
                image, if any (else 0).
             . 'xM','yM','zM','cM' : The pixel coordinates of the maximum value in the associated,
                image, if any (else 0).
             . 'pi' : value of pi, i.e. 3.1415926..
             . 'e' : value of e, i.e. 2.71828..
             . '?' or 'u' : a random value between [0,1], following an uniform distribution.
             . 'g' : a random value, following a gaussian distribution of variance 1
                (roughly in [-5,5]).
        _ These special operators can be used :
             . ';' : expression separator. The returned value is always the last encountered
                expression. For instance expression '1;2;pi' is evaluated as '3.14159'.
             . '=' : variable assignment. Parser variables can only refer to numerical values.
                Variable names are case-sensitive. Use this operator in conjunction with ';' to
                define complex evaluable expressions, such as 't=cos(x);3*t^2+2*t+1'.
                These parser variables are not accessible outside the evaluated expression.
        _ The following specific functions are also defined :
             . 'if(expr_cond,expr_then,expr_else)' : return value of 'expr_then' or 'expr_else',
                depending on the value of 'expr_cond' (0=false, other=true). For instance,
                G'MIC command '-fill if(x%10==0,255,i)' will draw blank vertical lines on every 10th
                column of an image.
             . '?(max)' or '?(min,max)' : return a random value between [0,max] or [min,max],
                following an uniform distribution. 'u(max)' and 'u(min,max)' mean the same.
             . 'i(a,_b,_c,_d,_borders)' : return the value of the pixel located at position
                (a,b,c,d) in the associated image, if any (else 0). Border conditions can be
                { 0=dirichlet | 1=neumann | 2=cyclic }. Omitted coordinates are replaced by their
                default values which are respectively equal to x, y, z, c and 0. For instance,
                command '-fill 0.5*(i(x+1)-i(x-1))' will estimate the X-derivative of an image.

### ** Management of global variables :

      - In a G'MIC processing pipeline, global variable management can be achieved through the use
         of the global stack (to store the variables), in conjunction with the mathematical parser
         (to update the variable values). For instance, a do..while loop with a custom counter
         would be typically written as : '-p[0] 0 -do -e ~0 -pr[-1] {~0+1} -while {~0<10} -pp[0]'.
      - Manipulation of the global stack is done with one of these three commands :
         '-push' (eq. to '-p'), '-pop' (eq. to '-pp') and '-pushr' (eq. to '-pr').
      - Accessing the content of the global stack is done either through the '@{*,subset}' or
         '~ind' substituting expressions.

### ** Custom commands :

      - Custom commands can be defined by the user, through the use of G'MIC command files.
      - A command file is a simple ascii text file, where each line starts either by
         'command_name : substitution' or 'substitution (continuation)' or '# comment'.
      - The name of a custom command may contain the characters 'a-z','A-Z','0-9' and '_'.
      - Any '# comment' expression found in a custom command file is discarded by the G'MIC
         interpreter, wherever it is located in a line.
      - A default command file is already provided within the G'MIC package. It is located
         at 'http://gmic.sourceforge.net/gmic_def.xxxx', where 'xxxx' must be replaced by
         the 4 digits of the current G'MIC version number. Looking at it is a good start to learn
         more on creating your own custom commands. All the commands from this default command file
         are in fact already included by default in the G'MIC interpreter.
      - The default command file located at 'http://gmic.sourceforge.net/gmic_def.xxxx' may be
         updated/corrected by the G'MIC developers. You can download and include it with the
         '-command' (or -'m') directive to update your default command definitions as well.
      - In custom commands, expressions starting with '$' are substituted this way :
        _ '$#' is substituted by the number of specified arguments.
        _ '$?' is substituted by a string telling about the command subset restriction (only useful
           when custom commands need to output descriptive messages).
        _ '$i' and '${i}' are both substituted by the i-th specified argument. Negative indices
           such as '$[-j}' are allowed and refer to the j^th latest argument. '$0' is substituted by
           the custom command name.
        _ '${i=default}' is substituted by the value of $i (if defined) or by its new default value
           'default' else ('default' may be a $-expression as well).
        _ '${subset}' is substituted by the arguments values (separated by commas ',') of a
           specified argument subset. For instance expression '${2--2}' is substitued by all
           specified arguments except the first and the last ones. Useful expression '${^0}' is
           substituted by all specified arguments.
      - Specifying arguments may be skipped when invoking a custom command, by replacing them by
         commas ',' as in expression '-flower ,,3'. Omitted arguments are set to their default
         values, which must be thus explicitely defined in the code of the corresponding custom
         command (using expressions as '${1=default}').

### ** Image and data viewers :

      - G'MIC has some very handy embedded visualization modules, for 1d signals (command '-plot'),
         1d/2d/3d images (command '-display') and 3d objects (command '-display3d'). They allow to
         interactively view and explore the selected image datasets.
      - The following keyboard shortcuts are available in the interactive viewers :
        _ CTRL+D : Increase window size.
        _ CTRL+C : Decrease window size.
        _ CTRL+R : Reset window size.
        _ CTRL+F : Toggle fullscreen mode.
        _ CTRL+S : Save current window snapshot as a numbered file 'CImg_xxxx.bmp'.
        _ CTRL+O : Save current instance of the viewed data, as a numbered file 'CImg_xxxx.cimg'.
      - Shortcuts specific to the 1d/2d/3d image viewer :
        _ CTRL+P             : Play stack of slices as a movie (for volumetric 3d images).
        _ CTRL+(mousewheel)  : Zoom in/out.
        _ SHIFT+(mousewheel) : Go left/right.
        _ ALT+(mousewheel)   : Go up/down.
        _ Numeric PAD        : Zoom in/out (+/-) and move through zoomed image (digits).
        _ BACKSPACE          : Reset zoom scale.
      - Shortcuts specific to the 3d object viewer :
        _ (mouse)+(left mouse button)   : Rotate object.
        _ (mouse)+(right mouse button)  : Zoom object.
        _ (mouse)+(middle mouse button) : Shift object.
        _ (mousewheel)                  : Zoom in/out.
        _ CTRL+F1 .. CTRL+F6            : Set 3d rendering mode.
        _ CTRL+Z                        : Enable/disable z-buffered rendering.
        _ CTRL+A                        : Show/hide 3d axes.
        _ CTRL+G                        : Save 3d object, as a numbered file 'CImg_xxxx.off'.
        _ CTRL+T                        : Switch between single/double-sided modes.

### ** Command reference :

     All recognized G'MIC commands are listed below, classified by themes.
     When several choices of command arguments are possible, they appear separated by '|'.
     An argument specified inside '[]' or starting by '_' is optional except when standing for an
     existing image [indice]. In this case, the '[]' characters are mandatory when writting the
     item. A command marked with (*) is available for all image types, else only for the default
     'float' pixel datatype.

## Global options

-help (*)
_command

            Display help (optionally for specified command only) and quit.
            (eq. to '-h').

-debug (*)

            Activate debug mode.
            When activated, this mode outputs additionnal log messages describing the
            internal state of the interpreter.

## Mathematical operators and functions

-add
value |
[indice] |
filename |
'formula' |
(no args)

            Add specified value, image, file or mathematical expression to selected images,
            or compute the pointwise sum of selected images.
            (eq. to '-+').

-sub
value |
[indice] |
filename |
'formula' |
(no args)

            Subtract specified value, image, file or mathematical expression to selected images,
            or compute the pointwise difference of selected images.
            (eq. to '--').

-mul
value |
[indice] |
filename |
'formula' |
(no args)

            Multiply selected images by specified value, image, file or mathematical expression,
            or compute the pointwise product of selected images.
            (eq. to '-*').

-mmul
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the matrix product of selected matrices/vectors by specified value, image, file or
            mathematical expression, or compute the matrix products of selected images.
            (eq. to '-**').

-div
value |
[indice] |
filename |
'formula' |
(no args)

            Divide selected image by specified value, image, file or mathematical expression,
            or compute the pointwise quotient of selected images.
            (eq. to '-/').

-pow
value |
[indice] |
filename |
'formula' |
(no args)

            Raise selected image to the power of specified value, image, file or mathematical
            expression, or compute the pointwise sequential powers of selected images.
            (eq. to '-^').

-min
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the minimum between selected images and specified value, image, file or
            mathematical expression, or compute the pointwise minima between selected images.

-max
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the maximum between selected images and specified value, image, file or
            mathematical expression, or compute the pointwise maxima between selected images.

-mod
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the modulo of selected images with specified value, image, file or mathematical
            expression, or compute the pointwise sequential modulo of selected images.

-and
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise AND of selected images with specified value, image, file or mathematical
            expression, or compute the pointwise sequential bitwise AND of selected images.

-or
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise OR of selected images with specified value, image, file or mathematical
            expression, or compute the pointwise sequential bitwise OR of selected images.

-xor
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise XOR of selected images with specified value, image, file or mathematical
            expression, or compute the pointwise sequential bitwise XOR of selected images.

-bsl
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise left shift of selected images with specified value, image, file or
            mathematical expression, or compute the pointwise sequential bitwise left shift of
            selected images.
            (eq. to '-<<').

-bsr
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise right shift of selected images with specified value, image, file or
            mathematical expression, or compute the pointwise sequential bitwise right shift of
            selected images.
            (eq. to '->>').

-rol
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise left rotation of selected images with specified value, image, file or
            mathematical expression, or compute the pointwise sequential bitwise left rotation of
            selected images.

-ror
value |
[indice] |
filename |
'formula' |
(no args)

            Compute the bitwise right rotation of selected images with specified value, image, file or
            mathematical expression, or compute the pointwise sequential bitwise right rotation of
            selected images.

-cos

            Compute the pointwise cosine of selected images.

-sin

            Compute the pointwise sine of selected images.

-sinc

            Compute the pointwise sinc function of selected images.

-tan

            Compute the pointwise tangent of selected images.

-cosh

            Compute the pointwise hyperbolic cosine of selected images.

-sinh

            Compute the pointwise hyperbolic sine of selected images.

-tanh

            Compute the pointwise hyperbolic tangent of selected images.

-acos

            Compute the pointwise arc-cosine of selected images.

-asin

            Compute the pointwise arc-sine of selected images.

-atan

            Compute the pointwise arc-tangent of selected images.

-atan2
[indice]

            Compute the pointwise oriented arc-tangent of selected images.
            Each selected image is regarded as the y-argument of the arc-tangent function, while the
            specified image gives the corresponding x-argument.

-abs

            Compute the pointwise absolute values of selected images.

-sign

            Compute the pointwise sign of selected images.

-sqr

            Compute the pointwise square function of selected images.

-sqrt

            Compute the pointwise square root of selected images.

-exp

            Compute the pointwise exponential of selected images.

-log

            Compute the pointwise logarithm of selected images.

-log10

            Compute the pointwise logarithm_10 of selected images.

## Basic pixel manipulation

-endian (*)

            Reverse data endianness of selected images.

-set
value,_x,_y,_z,_c

            Set pixel value in selected images, at specified coordinates.
            (eq. to '-=').
            If specified coordinates are outside the image bounds, no action is performed.
            Default values for 'x','y','z','c' are '0'.

-fill
value1,_value2,.. |
[indice] |
formula

            Fill selected images with values read from the specified value list, existing image
            or mathematical expression.
            (eq. to '-f').

-threshold
value[%],_soft |
(no args)

            Threshold values of selected images.
            (eq. to '-t').
            'soft' can be { 0=hard-thresholding | 1=soft-thresholding }.
            (noargs) runs interactive mode (uses the instant window [0] if opened).

-cut
{ value0[%] | [indice0] },{ value1[%] | [indice1] } |
[indice] |
(no args)

            Cut values of selected images in specified range.
            (eq. to '-c').
            (noargs) runs interactive mode (uses the instant window [0] if opened).

-normalize
{ value0[%] | [indice0] },{ value1[%] | [indice1] }
[indice]

            Linearly normalize values of selected images in specified range.
            (eq. to '-n').

-round
rounding_value>=0,_rounding_type

            Round values of selected images.
            'rounding_type' can be { -1=backward | 0=nearest | 1=forward }.

-equalize
nb_levels>0[%],_value0[%],_value1[%]

            Equalize histograms of selected images.
            If value range is specified, the equalization is done only for pixels in the specified
            value range.

-quantize
nb_levels>0,_preserve_value_range={ 0 | 1 }

            Uniformly quantize selected images.

-noise
std_variation>=0[%],_noise_type

            Add random noise to selected images.
            'noise_type' can be { 0=gaussian | 1=uniform | 2=salt&pepper | 3=poisson | 4=rice }.

-rand
value0,value1

            Fill selected images with random values uniformly distributed in the specified range.

-norm

            Compute the pointwise euclidean norm of vector-valued pixels in selected images.

-orientation

            Compute the pointwise orientation of vector-valued pixels in selected images.

-map
[indice] |
predefined_palette

            Map specified vector-valued palette to selected indexed scalar images.
            'predefined_palette' can be { 0=default | 1=rainbow | 2=cluster }.

-index
{ [indice] | predefined_palette },_is_dithered={ 0 | 1 },_map_palette={ 0 | 1 }

            Index selected vector-valued images by specified vector-valued palette.
            'predefined_palette' can be { 0=default | 1=rainbow | 2=cluster }.

## Color base conversion

-rgb2hsv

            Convert selected images from RGB to HSV colorbases.

-rgb2hsl

            Convert selected images from RGB to HSL colorbases.

-rgb2hsi

            Convert selected images from RGB to HSI colorbases.

-rgb2yuv

            Convert selected images from RGB to YUV colorbases.

-rgb2ycbcr

            Convert selected images from RGB to YCbCr colorbases.

-rgb2xyz

            Convert selected images from RGB to XYZ colorbases.

-rgb2lab

            Convert selected images from RGB to Lab colorbases.

-rgb2cmy

            Convert selected images from RGB to CMY colorbases.

-rgb2cmyk

            Convert selected images from RGB to CMYK colorbases.

-hsv2rgb

            Convert selected images from HSV to RGB colorbases.

-hsl2rgb

            Convert selected images from HSL to RGB colorbases.

-hsi2rgb

            Convert selected images from HSI to RGB colorbases.

-yuv2rgb

            Convert selected images from YUV to RGB colorbases.

-ycbcr2rgb

            Convert selected images from YCbCr to RGB colorbases.

-xyz2rgb

            Convert selected images from XYZ to RGB colorbases.

-lab2rgb

            Convert selected images from Lab to RGB colorbases.

-cmy2rgb

            Convert selected images from CMY to RGB colorbases.

-cmyk2rgb

            Convert selected images from CMYK to RGB colorbases.

## Geometry manipulation

-resize
[indice],_interpolation,_borders,_cx,_cy,_cz,_cc |
{[indice_w] | width>0[%]},_{[indice_h] | height>0[%]},_{[indice_d] | depth>0[%]},
_{[indice_s] | spectrum>0[%]},_interpolation,_borders,_cx,_cy,_cz,_cc |
(noargs)

            Resize selected images with specified geometry.
            (eq. to '-r').
            'interpolation' can be { -1=none (memory content) | 0=none | 1=nearest | 2=average |
                                      3=linear | 4=grid | 5=bicubic | 6=lanczos }.
            'borders' can be { -1=none | 0=dirichlet | 1=neumann | 2=cyclic }.
            'cx,cy,cz,cc' set the centering mode when 'interpolation=0' (must be in [0,1]).
            Their default values are '0'.
            (noargs) runs interactive mode (uses the instant window [0] if opened).

-resize2x

            Resize selected images using the Scale2x algorithm.

-resize3x

            Resize selected images using the Scale3x algorithm.

-crop
x0[%],x1[%],_borders |
x0[%],y0[%],x1[%],y1[%],_borders |
x0[%],y0[%],z0[%],x1[%],y1[%],z1[%],_borders |
x0[%],y0[%],z0[%],c0[%],x1[%],y1[%],z1[%],c1[%],_borders |
(noargs)

            Crop selected images with specified region coordinates.
            'borders' can be { 0=dirichlet | 1=neumann }.
            (noargs) runs interactive mode (uses the instant window [0] if opened).

-autocrop
value1,value2,..

            Autocrop selected images by specified vector-valued intensity.

-channels
{ [indice0] | c0[%] },_{ [indice1] | c1[%] }

            Select specified channels of selected images.

-slices
{ [indice0] | z0[%] },_{ [indice1] | z1[%] }

            Select specified slices of selected images.

-lines
{ [indice0] | y0[%] },_{ [indice1] | y1[%] }

            Select specified lines of selected images.

-columns
{ [indice0] | x0[%] },_{ [indice1] | x1[%] }

            Select specified columns of selected images.

-rotate
angle,_borders,_interpolation,_cx[%],_cy[%],_zoom

            Rotate selected images with specified angle (in deg.).
            'borders' can be { 0=dirichlet | 1=neumann | 2=cyclic }.
            'interpolation' can be { 0=none | 1=linear | 2=bicubic }.
            When rotation center ('cx','cy') is specified, the size of the image is preserved.

-mirror
axis={ x | y | z | c }

            Mirror selected images along specified axis.

-shift
vx[%],_vy[%],_vz[%],_vc[%],_borders

            Shift selected images by specified displacement vector.
            'borders' can be { 0=dirichlet | 1=neumann | 2=cyclic }.

-transpose

            Transpose selected images.

-invert

            Compute the inverse of the selected matrices.

-solve
[indice]

            Solve linear system AX = B for selected B-vectors and specified A-matrix.

-eigen

            Compute the eigenvalues and eigenvectors of specified symmetric matrices.

-permute
permutation

            Permute selected image axes by specified permutation.
            'permutation' is a combination of the character set {x|y|z|c},
            e.g. 'xycz', 'cxyz', ...

-unroll
axis={ x | y | z | c }

            Unroll selected images along specified axis.

-split
axis={ x | y | z | c },_nb_parts |
patch_x>0,_patch_y>0,_patch_z>0,_patch_v>0,borders |
value,_keep_splitting_values={ + | - }

            Split selected images along specified axis, patch or scalar value.
            (eq. to '-s').
            'nb_parts' can be { 0=maximum split | >0=split in N parts | <0=split in parts of size -N }.
            'borders' can be { 0=dirichlet | 1=neumann }.

-append
axis={ x | y | z | c },_alignment

            Append selected images along specified axis.
            (eq. to '-a').
            'alignment' can be { p=left | c=center | n=right }.

-warp
[indice],_is_relative={ 0 | 1 },_interpolation={ 0 | 1 },_borders,_nb_frames>0

            Warp selected image with specified displacement field.
            'borders' can be { 0=dirichlet | 1=neumann | 2=cyclic }.

## Image filtering

-blur
std_variation>=0[%],_borders

            Blur selected images by quasi-gaussian recursive filter.
            'borders' can be { 0=dirichlet | 1=neumann }.

-bilateral
std_variation_s>0[%],std_variation_r>0

            Blur selected images by anisotropic bilateral filtering.
            'borders' can be { 0=dirichlet | 1=neumann }.

-denoise
std_variation_s>=0,_std_variation_p>=0,_patch_size>0,_lookup_size>0,_smoothness,
_fast_approx={ 0 | 1 }

            Denoise selected images by non-local patch averaging.

-smooth
amplitude>=0,_sharpness>=0,_anisotropy,_alpha,_sigma,_dl>0,_da>0,_precision>0,
interpolation,_fast_approx={ 0 | 1 } |
nb_iterations>=0,_sharpness>=0,_anisotropy,_alpha,_sigma,_dt>0,0 |
[indice],_amplitude>=0,_dl>0,_da>0,_precision>0,_interpolation,_fast_approx={ 0 | 1 } |
[indice],_nb_iters>=0,_dt>0,0

            Smooth selected images anisotropically using diffusion PDE's, with specified field of
            diffusion tensors.
            'anisotropy' must be in [0,1].
            'interpolation' can be { 0=nearest | 1=linear | 2=runge-kutta }.

-median
radius>=0

            Apply median filter of specified radius on selected images.

-sharpen
amplitude>=0 |
amplitude>=0,1,_edge>=0,_alpha,_sigma

            Sharpen selected images by inverse diffusion or shock filters methods.

-convolve
[indice],_borders

            Convolve selected images by specified mask.
            'borders' can be { 0=dirichlet | 1=neumann }.

-correlate
[indice],_borders

            Correlate selected images by specified mask.
            'borders' can be { 0=dirichlet | 1=neumann }.

-erode
size>=0' |
size_x>=0,size_y>=0,_size_z>=0 |
[indice],_borders

            Erode selected images by a rectangular or the specified structuring element.
            'borders' can be { 0=dirichlet | 1=neumann }.

-dilate
size>=0 |
size_x>=0,size_y>=0,size_z>=0 |
[indice],_borders

            Dilate selected images by a rectangular or the specified structuring element.
            'borders' can be { 0=dirichlet | 1=neumann }.

-inpaint
[indice]

            Inpaint selected images by specified mask.

-gradient
{ x | y | z }..{ x | y | z },_scheme |
(no args)

            Compute the gradient components (first derivatives) of selected images.
            'scheme' can be { -1=backward | 0=centered | 1=forward | 2=sobel |
                               3=rotation-invariant (default) | 4=recursive }.
            (no args) compute all significant 2d/3d components.

-structuretensors
_scheme

            Compute the structure tensor field of selected images.
            'scheme' can be { 0=centered | 1=forward-backward1 | 2=forward-backward2 }.

-edgetensors
sharpness>=0,_anisotropy,_alpha,_sigma,is_sqrt={ 0 | 1 }

            Compute the diffusion tensors of selected images for edge-preserving smoothing algorithms.
            'anisotropy' must be in [0,1].

-hessian
{ xx | xy | xz | yy | yz | zz }..{ xx | xy | xz | yy | yz | zz } |
(no args)

            Compute the hessian components (second derivatives) of selected images.
            (no args) compute all significant components.

-haar
scale>0

            Compute the direct haar multiscale wavelet transform of selected images.

-ihaar
scale>0

            Compute the inverse haar multiscale wavelet transform of selected images.

-fft

            Compute the direct fourier transform of selected images.

-ifft

            Compute the inverse fourier transform of selected images.

## Image creation and drawing

-histogram
nb_levels>0[%],_val0[%],_val1[%]

            Compute the histogram of selected images.
            If value range is specified, the histogram is estimated only for pixels in the specified
            value range.

-distance
isovalue

            Compute the unsigned distance function to specified isovalue.

-eikonal
nb_iterations>=0,_band_size>=0

            Compute iterations of the eikonal equation (signed distance function) on selected images.

-watershed
[indice],_fill_lines={ 0 | 1 }

            Compute the watershed transform of selected images.

-label

            Label connected components in selected images.

-displacement
[indice],_smoothness>=0,_precision>0,_nb_scales>=0,iteration_max>=0,
is_backward={ 0 | 1 }

            Estimate displacement field between selected images and specified source.
            If 'nbscales'=0, the number of needed scales is estimated from the image size.

-sort
_ordering={ + | - },_axis={ x | y | z | c } |

            Sort pixel values of selected images.

-mse

            Compute MSE (Mean-Squared Error) matrix between selected images.

-psnr
_max_value

            Compute PSNR (Peak Signal-to-Noise Ratio) matrix between selected images.

-point
x[%],y[%],_z[%],_opacity,_color1,..

            Set specified colored pixel on selected images.
            Default color value is '0'.

-line
x0[%],y0[%],x1[%],y1[%],_opacity,_color1,..'

            Draw specified colored line on selected images.
            Default color value is '0'.

-polygon
N,x1[%],y1[%],..,xN[%],yN[%],_opacity,_color1,..

            Draw specified colored N-vertices polygon on selected images.
            Default color value is '0'.

-spline
x0,y0,u0,v0,x1,y1,u1,v1,_opacity,_color1,..

            Draw specified colored spline curve on selected images.
            Default color value is '0'.

-ellipse
x[%],y[%],r[%],R[%],_angle,_opacity,_color1,..

            Draw specified colored ellipse on selected images.
            Default color value is '0'.

-text
text,_x[%],_y[%],_font_height>0,_opacity,_color1,..

            Draw specified colored text string on selected images.
            Exact pre-defined sizes are '13','24','32' and '57'.
            Default color value is '0'.

-graph
[indice],_plot_type,_vertex_type,_ymin,_ymax,_opacity,_color1,.. |
'formula',_resolution>=0,_plot_type,_vertex_type,_xmin,xmax,_ymin,_ymax,_opacity,_color1,..

            Draw specified function graph on selected images.
            'plot_type' can be { 0=none | 1=lines | 2=splines | 3=bar }.
            'vertex_type' can be { 0=none | 1=points | 2,3=crosses | 4,5=circles | 6,7=squares }.
            Default color value is '0'.

-axes
x0,x1,y0,y1,_opacity,_color1,..

            Draw xy-axes on selected images.
            Default color value is '0'.

-quiver
[indice],_sampling>0,_factor,_is_arrow={ 0 | 1 },_opacity,_color1,..

            Draw specified 2d vector/orientation field on selected images.
            Default color value is '0'.

-flood
x[%],_y[%],_z[%],_tolerance>=0,_opacity,_color1,..

            Flood-fill selected images using specified value and tolerance.
            Default color value is '0'.

-image
[indice],_x[%],_y[%],_z[%],_c[%],_opacity,_[indice_mask]

            Draw specified sprite image on selected images.

-object3d
[indice],_x[%],_y[%],_z,_opacity,_is_zbuffer={ 0 | 1 }

            Draw specified 3d object on selected images.

-plasma
alpha,_beta,_opacity

            Draw a random colored plasma on selected images.

-mandelbrot
z0r,z0i,z1r,z1i,_iteration_max>=0,_is_julia={ 0 | 1 },_c0r,_c0i,_opacity

            Draw mandelbrot/julia fractal on selected images.

## List manipulation

-remove (*)

            Remove selected images.
            (eq. to '-rm').

-keep (*)

            Keep only selected images.
            (eq. to '-k').

-move (*)
position

            Move selected images at specified position.
            (eq. to '-mv').

-reverse (*)

            Reverse positions of selected images.

-name (*)
name

            Set name of selected images.

## 3d rendering

-point3d
x0,y0,z0

            Create a new 3d point at specified coordinates.

-line3d
x0,y0,z0,x1,y1,z1

            Create a new 3d line at specified coordinates.

-triangle3d
x0,y0,z0,x1,y1,z1,x2,y2,z2

            Create a new 3d triangle at specified coordinates.

-quadrangle3d
x0,y0,z0,x1,y1,z1,x2,y2,z2,x3,y3,z3

            Create a new 3d quadrangle at specified coordinates.

-circle3d
x0,y0,z0,radius>=0

            Create a new 3d circle at specified coordinates.

-box3d
size |
size_x,size_y,size_z

            Create a new 3d box at (0,0,0), with specified geometry.

-cone3d
radius,_size_z,_nb_subdivisions>0

            Create a new 3d cone at (0,0,0), with specified geometry.

-cylinder3d
radius,_height,_nb_subdivisions>0

            Create a new 3d cylinder at (0,0,0), with specified geometry.

-torus3d
radius1,_radius2,_nb_subdivisions1>0,_nb_subdivisions2>0

            Create a new 3d torus at (0,0,0), with specified geometry.

-plane3d
size1_size2,_nb_subdivisions1>0,_nb_subdisivions2>0

            Create a new 3d plane at (0,0,0), with specified geometry.

-sphere3d
radius,_nb_recursions>=0

            Create a new 3d sphere at (0,0,0), with specified geometry.

-elevation3d
z-factor |
[indice] |
'formula',_x0,_y0,_x1,y1,_dx[%],_dy[%] |
(no args)

            Create 3d elevation of selected images or specified formula, with specified elevation map.
            If a z-factor is specified, each elevation map is computed as the pointwise L2 norm of the
            selected images. Else, elevation values are taken from the specified image or formula.

-isoline3d
isovalue[%] |
'formula',value,_x0,_y0,_x1,_y1,_dx>0[%],_dy>0[%]

            Extract 3d isolines with specified value from selected images or from specified formula.

-isosurface3d
isovalue[%] |
'formula',value,_x0,_y0,_z0,_x1,_y1,_z1,_dx>0[%],_dy>0[%],_dz>0[%]

            Extract 3d isosurfaces with specified value from selected images or from specified formula.

-streamline3d
x,y,z,_L>=0,_dl>0,_interp,_is_backward={ 0 | 1 },_is_oriented={ 0 | 1 } |
'formula',x,y,z,_L>=0,_dl>0,_interp,_is_backward={ 0 | 1 },_is_oriented={ 0 | 1 }

            Extract 3d streamlines from selected vector fields or from specified formula.
            'interp' can be { 0=nearest integer | 1=1st-order | 2=2nd-order | 3=4th-order }.

-add3d
tx,_ty,_tz |
[indice3d] |
(noargs)

            Shift selected 3d objects with specified displacement vector, or merge them with specified
            3d object, or merge all selected 3d objects together.
            (eq. to '-+3d').

-sub3d
tx,_ty,_tz

            Shift selected 3d objects with the opposite of specified displacement vector.
            (eq. to '--3d').

-mul3d
factor |
factor_x,factor_y,_factor_z

            Scale selected 3d objects isotropically or anisotropically, with specified factors.
            (eq. to '-*3d').

-div3d
factor |
factor_x,factor_y,_factor_z

            Scale selected 3d objects isotropically or anisotropically, with the inverse of specified
            factors.
            (eq. to '-/3d').

-center3d

            Center selected 3d objects at (0,0,0).
            (eq. to '-c3d').

-normalize3d

            Normalize size of selected 3d objects.
            (eq. to '-n3d').

-rotate3d
u,v,w,angle

            Rotate selected 3d objects around specified axis with specified angle (in deg.).
            (eq. to '-rot3d').

-color3d
R,G,B,_opacity

            Set color and opacity of selected 3d objects.
            (eq. to '-col3d').

-opacity3d
opacity

            Set opacity of selected 3d objects.
            (eq. to '-o3d').

-reverse3d

            Reverse orientation of selected 3d objects.
            (eq. to '-r3d').

-primitives3d
mode

            Convert primitives of selected 3d objects.
            (eq. to '-p3d').
            'mode' can be { 0=points | 1=segments | 2=no-textures }.

-split3d

            Split selected 3d objects into 6 feature vectors :
            { header, sizes, vertices, primitives, colors, opacities }.
            (eq. to '-s3d').
            To recreate the 3d object, append these 6 images along the y-axis.

-light3d
position_x,position_y,position_z |
[indice] |
(no args)

            Set the light coordinates or the light texture for 3d rendering.
            (eq. to '-l3d').
            (noargs) resets the 3d light to default.

-focale3d
focale>=0

            Set 3d focale.
            (eq. to '-f3d').
            Set 'focale' to 0 to enable parallel projection (instead of perspective).

-pose3d
value11,..,value12 |
(noargs)

            Set the coefficients of the 3d pose matrix.
            (noargs) resets the 3d pose matrix to default.

-specl3d
value

            Set amount of 3d specular light.
            (eq. to '-sl3d').

-specs3d
value

            Set shininess of 3d specular light.
            (eq. to '-ss3d').

-double3d
is_double={ 0 | 1 }

            Enable/disable double-sided mode for 3d rendering.
            (eq. to '-db3d').

-mode3d
mode

            Set static 3d rendering mode.
            (eq. to '-m3d').
            'mode' can be { -1=bounding-box | 0=pointwise | 1=linear | 2=flat | 3=flat-shaded |
                             4=gouraud-shaded | 5=phong-shaded }.

-moded3d
mode

            Set dynamic 3d rendering mode.
            (eq. to '-md3d').
            'mode' can be { -1=bounding-box | 0=pointwise | 1=linear | 2=flat | 3=flat-shaded |
                             4=gouraud-shaded | 5=phong-shaded }.

-background3d
R,_G,_B |
[indice] |
(no args)

            Define background from specified color or existing image for 3d rendering.
            (eq. to '-b3d').
            (no args) resets the background to default.

## Program control and environment

-skip (*)
item

            Do nothing but skip specified item.

-return (*)

            Return from current custom command.

-exec (*)
command

            Execute external command using a system call.
            (eq. to '-x').

-do (*)

            Start a 'do..while' block.

-while (*)
condition

            End a 'do..while' block and go back to associated '-do'
            if specified condition is verified.
            'condition' must be a number standing for { 0=false | other=true }.

-repeat (*)
nb_iterations

            Start iterations of a 'repeat..done' block.

-done (*)

            End a 'repeat..done' block, and go to associated '-repeat' position, if iterations remain.

-break (*)

            Break current 'repeat..done' or 'do..while' block.
            (eq. to '-b').

-continue (*)

            Continue to next iteration of current 'repeat..done' or 'do..while' block.

-if (*)
condition

            Start a 'if..[elif]..[else]..endif' block and test
            if specified condition is verified.
            'condition' must be a number standing for { 0=false | other=true }.

-elif (*)
condition

            Start a 'elif..[else]..endif' block if previous '-if' was not verified
            and test if specified condition is verified.

-else (*)

            Execute following commands if previous '-if' or '-elif' conditions failed.

-endif (*)

            End a 'if..[elif]..[else]..endif' block.

-local (*)

            Start a 'local..endlocal' block, with selected images.
            (eq. to '-l').

-endlocal (*)

            End a 'local..endlocal' block.
            (eq. to '-endl').

-check (*)
expression

            Evaluate expression, and display an error message if it is not verified.

-quit (*)

            Quit interpreter.
            (eq. to '-q').

-push (*)
item

            Push specified item on the global stack at selected positions.
            (eq. to '-p').
            Command subset (if any) stands for stack indices instead of image indices.
            If no subset is specified, the item is pushed at the end of the global stack.

-pushr (*)
item

            Replace item on the global stack by specified item, at selected positions.
            (eq. to '-pr').
            Command subset (if any) stands for stack indices instead of image indices.

-pop (*)

            Pop items from the global stack at selected positions.
            (eq. to '-pp').
            Command subset (if any) stands for stack indices instead of image indices.

-error (*)
message

            Print specified error message, on the standard output, and quit interpreter.
            Command subset (if any) stands for displayed scope indices instead of image indices.

-progress (*)
0<=value<=100 |
-1

            Set the progress indice of the current processing pipeline.
            This command is useful only when G'MIC is used by an embedding application.

## Input/output

-input (*)
filename |
[indice]x_nb_copies>0 |
{ width>0[%] | [indice_w] },{ _height>0[%] | [indice_h] },{ _depth>0[%] | [indice_d] },
{ _spectrum>0[%] | [indice_s] },_value1,_value2,.. |
(value1{,|;|/|^}value2{,|;|/|^}..)

            Insert a new image taken from a filename or from a copy of an existing image ['indice'],
            or insert new image with specified dimensions and values.
            (eq. to '-i' | (no args)).

-output (*)
filename,_format_options

            Output selected images as one or several numbered file(s).
            (eq. to '-o').

-verbose (*)
level |
{ + | - }

            Set or increment/decrement the verbosity level.
            (eq. to '-v').
            When 'level'>=0, G'MIC status messages are displayed on the standard output.
            Default value for the verbosity level is 0.

-print (*)

            Output informations on selected images, on the standard output.

-echo (*)
message

            Output specified message, on the standard output.
            (eq. to '-e').
            Command subset (if any) stands for displayed scope indices instead of image indices.

-warning (*)
message

            Print specified warning message, on the standard output.
            Command subset (if any) stands for displayed scope indices instead of image indices.

-command (*)
filename |
"string"

            Import G'MIC custom command(s) from specified file or string.
            (eq. to '-m').
            Imported commands are available directly after the '-command' invokation.

-type (*)
datatype

            Set pixel datatype for all images of the list.
            'datatype' can be { bool | uchar | char | ushort | short | uint |
                                 int | float | double }.

-shell (*)

            Start interactive shell environment, with selected images.

-shared (*)
x0,x1,y,z,v |
y0,y1,z,v |
z0,z1,v |
v0,v1 |
(no args)

            Insert shared buffers from (opt. points/lines/planes/channels of) selected images.

-display

            Display selected images in an interactive viewer (use the instant window [0] if opened).
            (eq. to '-d').

-display3d

            Display selected 3d objects in an interactive viewer (use the instant window [0] if opened).
            (eq. to '-d3d').

-plot
_plot_type,_vertex_type,_xmin,_xmax,_ymin,_ymax |
'formula',_resolution>=0,_plot_type,_vertex_type,_xmin,xmax,_ymin,_ymax

            Display selected image or formula in an interactive viewer (use the instant window [0] if
            opened).
            'plot_type' can be { 0=none | 1=lines | 2=splines | 3=bar }.
            'vertex_type' can be { 0=none | 1=points | 2,3=crosses | 4,5=circles | 6,7=squares }.
            'xmin','xmax','ymin','ymax' set the coordinates of the displayed xy-axes.

-window
_width>=-1,_height>=-1,_normalization,_fullscreen,_title

            Display selected images into an instant window with specified size, normalization type,
            fullscreen mode and title.
            (eq. to '-w').
            If 'width' or 'height' is set to -1, the corresponding dimension is adjusted to the window
            or image size.
            'width'=0 or 'height'=0 closes the instant window.
            'normalization' can be { -1=keep same | 0=none | 1=always | 2=1st-time | 3=auto }.
            'fullscreen' can be { -1=keep same | 0=no | 1=yes }.
            You can manage up to 10 different instant windows by using the numbered variants
            '-w0' (default, eq. to '-w'),'-w1',..,'-w9' of the command '-w'.

-wait
delay |
(no args)

            Wait for a given delay (in ms) or for an user event occuring on the selected instant window.
            'delay' can be { <0=delay+flush |  0=event | >0=delay }.
            Command subset (if any) stands for instant window indices instead of image indices.

-select
feature

            Interactively select a feature from selected images (use the instant window [0] if opened).
            'feature' can be { 0=point | 1=segment | 2=rectangle | 3=ellipse }.
            The retrieved feature is returned as a vector containing the feature coordinates.

## Shortcuts for native commands

-h (*)
eq. to '-help'.
-+
eq. to '-add'.
--
eq. to '-sub'.
-*
eq. to '-mul'.
-**
eq. to '-mmul'.
-/
eq. to '-div'.
-^
eq. to '-pow'.
-<<
eq. to '-bsl'.
->>
eq. to '-bsr'.
-=
eq. to '-set'.
-f
eq. to '-fill'.
-t
eq. to '-threshold'.
-c
eq. to '-cut'.
-n
eq. to '-normalize'.
-r
eq. to '-resize'.
-s
eq. to '-split'.
-a
eq. to '-append'.
-rm (*)
eq. to '-remove'.
-k (*)
eq. to '-keep'.
-mv (*)
eq. to '-move'.
-+3d
eq. to '-add3d'.
--3d
eq. to '-sub3d'.
-*3d
eq. to '-mul3d'.
-/3d
eq. to '-div3d'.
-c3d
eq. to '-center3d'.
-n3d
eq. to '-normalize3d'.
-rot3d
eq. to '-rotate3d'.
-col3d
eq. to '-color3d'.
-o3d
eq. to '-opacity3d'.
-r3d
eq. to '-reverse3d'.
-p3d
eq. to '-primitives3d'.
-s3d
eq. to '-split3d'.
-l3d
eq. to '-light3d'.
-f3d
eq. to '-focale3d'.
-sl3d
eq. to '-specl3d'.
-ss3d
eq. to '-specs3d'.
-db3d
eq. to '-double3d'.
-m3d
eq. to '-mode3d'.
-md3d
eq. to '-moded3d'.
-b3d
eq. to '-background3d'.
-x (*)
eq. to '-exec'.
-b (*)
eq. to '-break'.
-l (*)
eq. to '-local'.
-endl (*)
eq. to '-endlocal'.
-q (*)
eq. to '-quit'.
-p (*)
eq. to '-push'.
-pr (*)
eq. to '-pushr'.
-pp (*)
eq. to '-pop'.
-e (*)
eq. to '-echo'.
-i (*)
eq. to '-input'.
-o (*)
eq. to '-output'.
-v (*)
eq. to '-verbose'.
-m (*)
eq. to '-command'.
-d
eq. to '-display'.
-d3d
eq. to '-display3d'.
-w
eq. to '-window'.

## Default custom commands

-ow
eq. to '-outputw'.
-outputw

            Output selected images by overwritting their original location (eq. to '-ow').

-op
eq. to '-outputp'.
-outputp
prefix

            Output selected images as prefixed versions of their original filenames (eq. to '-op').

-on
eq. to '-outputn'.
-outputn
filename

            Output selected images as automatically numbered filenames in repeat..done loops (eq. to '-or').

-d0
eq. to '-display0'.
-display0

            Display selected images with value normalization off (eq. to '-d0').

-split_tiles
M!=0,_N!=0,_is_homogeneous={ 0 | 1 }

            Split selected images as a MxN array of tiles.

-append_tiles
M>0,_N>0

            Append MxN selected tiles as a new image.

-replace_nan
_expression

            Replace all NaN values in selected images by specified expression.

-replace_inf
_expression

            Replace all infinite values in selected images by specified expression.

-roundify
_gamma>=0

            Apply roundify transformation on float-valued data, with specified gamma.

-strcmp
string1,string2

            Compare two strings and push resulting boolean on the global stack.

-apply_pose3d
p1,..,p12

            Apply 3d pose matrix to selected 3d objects.

-push_filename
"filename",_number1,_number2

            Push a numbered version of the specified filename on the global stack.

-push_maxsize

            Push the maximal size of selected images on the global stack.

-push_minsize

            Push the minimal size of selected images on the global stack.

-histogram_cumul
_nb_levels>0,_is_normalized={ 0 | 1 }

            Compute cumulative histogram of selected images.

-direction2rgb

            Compute RGB representation of selected 2d direction fields.

-vector2tensor

            Convert selected vector fields to corresponding diffusion tensor fields.

-fftpolar

            Compute Fourier transform of selected images, as centered magnitude/phase images.

-ifftpolar

            Compute inverse Fourier transform of selected images, from centered magnitude/phase images.

-dfft
eq. to '-display_fft'.
-display_fft

            Display Fourier transform of selected images, with centered log-module and argument (eq. to '-dfft').

-drgba
eq. to '-display_rgba'.
-display_rgba

            Render selected RGBA images over a checkerboard background (eq. to '-drgba').

-drgba
eq. to '-display_histogram'.
-display_histogram
_width>0,_height>0,_clusters>0,_max_value>0,_show_axes={ 0 | 1 }

            Render a channel-by-channel histogram (eq. to '-dh').

-gradient_norm

            Compute gradient norm of selected images.

-gradient_orientation
_dimension={1,2,3}

            Compute N-D gradient orientation of selected images.

-gradient2rgb
_orientation={ 0 | 1 }

            Compute RGB representation of 2d gradient of selected images.

-laplacian

            Compute Laplacian of selected images.

-gradient_derivative2

            Compute gradient-directed 2nd derivative of image(s).

-curvature

            Compute isophote curvatures on selected images.

-edges
_threshold>=0

            Estimate contours of selected images.

-isophotes
_nb_levels>0

            Render isophotes of selected images on a transparent background.

-topographic_map
_nb_levels>0,_smoothness

            Render selected images as topographic maps.

-segment_watershed
_threshold>=0

            Apply watershed segmentation on selected images.

-blur_x
_amplitude,_borders={ 0 | 1 }

            Blur selected images along the X-axis.

-blur_y
_amplitude,_borders={ 0 | 1 }

            Blur selected images along the Y-axis.

-blur_z
_amplitude,_borders={ 0 | 1 }

            Blur selected images along the Z-axis.

-blur_angular
_amplitude,_cx,_cy

            Apply angular blur on selected images.

-blur_radial
_amplitude,_cx,_cy

            Apply radial blur on selected images.

-blur_linear
_amplitude1,_amplitude2,_angle=0,_borders={ 0 | 1 }

            Apply linear blur on selected images, with specified angle and amplitudes.

-dog
_sigma1>=0[%],_sigma2>=0[%]

            Compute difference of gaussian on selected images.

-split_freq
smoothness>0[%]

            Split selected images into low and high frequency parts.

-compose_freq

            Compose selected low and high frequency parts into new images.

-normalize_local
_amplitude>=0,_radius>0,_n_smooth>=0[%],_a_smooth>=0[%],_cut={ 0 | 1 },_min=0,_max=255

            Normalize selected images locally.

-unsharp
_radius[%]>=0,_amount>=0,_threshold[%]>=0

            Apply unsharp mask on selected images.

-unsharp_octave
_nb_scales>0,_radius[%]>=0,_amount>=0,threshold[%]>=0

            Apply octave sharpening on selected images.

-convolve_fft

            Convolve selected images two-by-two through Fourier transforms.

-deconvolve_fft

            Deconvolve selected images two-by-two through Fourier transforms.

-bandpass
_min_freq[%],_max_freq[%]

            Apply bandpass filter to selected images.

-rgb2bayer
_start_pattern=0,_color=0

            Transform selected color images to RGB-Bayer sampled images.

-bayer2rgb
_GM_smoothness,_RB_smoothness1,_RB_smoothness2

            Transform selected RGB-Bayer sampled images to color images.

-pde_flow
_nb_iter>=0,_dt,_velocity_command,_sequence_flag={ 0 | 1 }

            Apply iterations of a generic PDE flow on selected images.

-heat_flow
_nb_iter>=0,_dt,_sequence_flag={ 0 | 1 }

            Apply iterations of the heat flow on selected images.

-meancurvature_flow
_nb_iter>=0,_dt,_sequence_flag={ 0 | 1 }

            Apply iterations of the mean curvature flow on selected images.

-tv_flow
_nb_iter>=0,_dt,_sequence_flag={ 0 | 1 }

            Apply iterations of the total variation flow on selected images.

-inpaint_flow
_nb_iter1>=0,_nb_iter2>=0,_dt>=0,_alpha,_sigma

            Apply iteration of the inpainting flow on selected images.

-richardson_lucy
amplitude>=0,_nb_iter>=0,_dt>=0,_regul>=0,_regul_type={ 0=Tikhonov | 1=meancurv. | 2=TV }

            Deconvolve image with the iterative Richardson-Lucy algorithm.

-remove_hotpixels
_mask_size>0, _threshold[%]>0

            Remove hot pixels in selected images.

-lic
_amplitude>0,_channels>0

            Generate LIC representation of vector field.

-complex2polar

            Compute complex to polar transforms of selected images.

-polar2complex

            Compute polar to complex transforms of selected images.

-transfer_histogram

            Transfer histogram of the last selected image to the other ones.

-normalize_sum

            Normalize selected images with a unitary sum.

-apply_gamma
gamma

            Apply gamma correction to selected images.

-negative

            Compute negative of selected images.

-tones
N>0

            Get N tones masks from selected images.

-t2
eq. to '-threshold2'.
-threshold2
_min,_max

            Threshold selected images between the two given values (eq. to '-t2').

-r2dx
eq. to '-resize2dx'.
-resize2dx
width>0,_interpolation_type={0,1,2,3,4,5}

            Resize selected images along the X-axis, preserving 2d ratio (eq. to '-r2dx').

-r3dx
eq. to '-resize3dx'.
-resize3dx
width>0,_interpolation_type={0,1,2,3,4,5}

            Resize selected images along the X-axis, preserving 3d ratio (eq. to '-r3dx').

-r2dy
eq. to '-resize2dy'.
-resize2dy
height>0,_interpolation_type={0,1,2,3,4,5}

            Resize selected images along the Y-axis, preserving 2d ratio (eq. to '-r2dy').

-r3dy
eq. to '-resize3dy'.
-resize3dy
height>0,_interpolation_type={0,1,2,3,4,5}

            Resize selected images along the Y-axis, preserving 3d ratio (eq. to '-r3dy').

-r3dz
eq. to '-resize3dz'.
-resize3dz
depth>0,_interpolation_type={0,1,2,3,4,5}

            Resize selected images along the Z-axis, preserving 3d ratio (eq. to '-r3dz').

-upscale_smart
width,height,_depth,smoothness>=0,_anisotropy=[0,1],sharpening>=0

            Upscale selected images with an edge-preserving algorithm.

-expand_x
size_x>=0,_borders={0,1,2}

            Expand selected images along the X-axis.

-expand_y
size_y>=0,borders={0,1,2}

            Expand selected images along the Y-axis.

-expand_z
size_z>=0,borders={0,1,2}

            Expand selected images along the Z-axis.

-expand_xy
size>=0,borders={0,1,2}

            Expand selected images along the XY-axes.

-expand_xyz
size>=0,borders={0,1,2}

            Expand selected images along the XYZ-axes.

-shrink_x
size_x>=0

            Shrink selected images along the X-axis.

-shrink_y
size_y>=0

            Shrink selected images along the Y-axis.

-shrink_z
size_z>=0

            Shrink selected images along the Z-axis.

-shrink_xy
size>=0

            Shrink selected images along the XY-axes.

-elevate
_depth,_is_plain,_is_colored

            Elevate selected 2d images into 3d volumes.

-array
_M>0,_N>0,_expand_type={0,1,2}

            Create MxN array from selected images.

-array_fade
_M>0,_N>0,0<=_fade_start<=100,0<=_fade_end<=100,_expand_type={0,1,2}

            Create MxN array from selected images.

-array_mirror
_N>=0,_dir={0,1,2},_expand_type={ 0 | 1 }

            Create 2^Nx2^N array from selected images.

-array_random
_Ms>0,_Ns>0,_Md>0,_Nd>0

            Create MdxNd array of tiles from selected MsxNs source arrays.

-array_pattern
_M>0,_N>0,_density>=0,_angle>=0,_zoom>=0,_opacity,_expand_type={0,1,2}

            Create random MxN array from selected images.

-taquin
_M>0,_N>0

            Create MxN taquin puzzle from selected images.

-grid
_M>0,_N>0

            Create MxN image grid from selected images.

-frame
_size_x>=0,_size_y>=0,_R,_G,_B,_A

            Insert RGBA-colored frame in selected images.

-frame_fuzzy
_size_x>=0,_size_y>=0,_fuzzyness>=0,_smoothness>=0,_R,_G,_B,_A

            Draw RGBA-colored fuzzy frame in selected images.

-frame_round
_sharpness>0,_size>=0,_smoothness,_R,_G,_B,_A

            Draw RGBA-colored round frame in selected images.

-rotate_tiles
_angle,_M>0,N>0

            Apply MxN tiled-rotation effect on selected images.

-shift_tiles
_M>0,_N>0,_amplitude

            Apply MxN tiled-shift effect on selected images.

-linearize_tiles
_M>0,_N>0

            Linearize MxN tiles on selected images.

-quadratize_tiles
_M>0,_N>0

            Quadratize MxN tiles on selected images.

-polaroid
_size1>=0,_size2>=0

            Create polaroid effect in selected images.

-drop_shadow
_offset_x[%],_offset_y[%],_smoothness[%]

            Drop shadow behind selected images.

-tetris
_scale>0

            Apply tetris effect on selected images.

-mosaic
_density>=0,_edges={ 0 | 1 }

            Create random mosaic from selected images.

-puzzle
_scale>=0

            Apply puzzle effect on selected images.

-sponge
_size>0

            Apply sponge effect on selected images.

-hearts
_density>=0

            Apply heart effect on selected images.

-color_ellipses
_count>0,_radius>=0,_opacity>=0

            Add random color ellipses to selected images.

-whirls
_texture>=0,_smoothness>=0,_darkness>=0,_lightness>=0

            Add random whirl texture to selected images.

-cartoon
_smoothness,_sharpening,_threshold>=0,_thickness>=0,_color>=0,quantization>0

            Apply cartoon effect on selected images.

-drawing
_amplitude>=0

            Apply drawing effect on selected images.

-draw_whirl
_amplitude>=0

            Apply whirl drawing effect on selected images.

-stencil
_radius[%]>=0,_smoothness>=0,_iterations>=0

            Apply stencil filter on selected images.

-stencilbw
_edges>=0,_smoothness>=0

            Apply B&W stencil effect on selected images.

-pencilbw
_size>=0,_amplitude>=0

            Apply B&W pencil effect on selected images.

-ditheredbw

            Create dithered B&W version of selected images.

-dotsbw

            Apply B&W dots effect on selected images.

-warhol
_M>0,_N>0,_smoothness>=0,_color>=0

            Create MxN Andy Warhol-like artwork from selected images.

-cubism
_nb_iter>=0,_bloc_size>0,_max_angle,_opacity,_smoothness>=0

            Apply cubism effect on selected images.

-glow
_amplitude>=0

            Add soft glow on selected images.

-old_photo

            Apply old photo effect on selected images.

-euclidean2polar
_cx,_cx,_n>0,_borders={0,1,2}

            Apply euclidean to polar transform on selected images.

-warp_perspective
_x-angle,_y-angle,_zoom>0,_x-center,_y-center,_borders={0,1,2}

            Warp selected images with perspective deformation.

-polar2euclidean
_cx,_cy,_n>0,_borders={0,1,2}

            Apply polar to euclidean transform on selected images.

-water
_amplitude>=0,_smoothness>=0

            Apply water deformation on selected images.

-wave
_amplitude>=0,_frequency>=0,_center_x,_center_y

            Apply wave deformation on selected images.

-twirl
_amplitude,_cx,_cy,_borders={0,1,2}

            Apply twirl deformation on selected images.

-map_sphere
_width>0,_height>0,_radius,_dilation>0

            Map selected images on a sphere.

-flower
_amplitude,_frequency,_offset_r[%],_angle,_cx,_cy,_borders={0,1,2}

            Apply flower deformation on selected images.

-zoom
_factor,_cx,_cy,_cz,_borders={0,1,2}

            Apply zoom factor to selected images.

-deform
_amplitude>=0

            Apply random smooth deformation on selected images.

-fish_eye
_x,_y,0<=_radius<=100,_amplitude>=0

            Apply fish-eye deformation on selected images.

-transform_polar
"expr_radius",_"expr_angle",_x_center,_y_center,_borders={ 0 | 1 }

            Apply user-defined transform on polar representation of selected images.

-kaleidoscope
_cx,_cy,_radius,_angle,_borders={0,1,2}

            Create kaleidoscope effect from selected images.

-spread
_dx>=0,_dy>=0,_dz>=0

            Spread pixel values of selected images randomly along x,y and z.

-shade_stripes
_frequency>=0,_direction={ 0 | 1 },_darkness>=0,_lightness>=0

            Add shade stripes to selected images.

-stripes_y
_frequency>=0

            Add vertical stripes to selected images.

-shadow_patch
_opacity>=0

            Add shadow patches to selected images.

-light_patch
_density>0,_darkness>=0,_lightness>=0

            Add light patches to selected images.

-light_relief
_ambient_light,_specular_light,_specular_size,_darkness,_xl,_yl,_zl,_zscale,_opacity_bumpmap={ 0 | 1 }

            Apply relief light to selected images.

-noise_hurl
_amplitude>=0

            Add hurl noise to selected images.

-pixelize
_scale_x>0,_scale_y>0,_scale_z>0

            Pixelize selected images with specified scales.

-paper_texture

            Add paper texture to selected images.

-mosaic_texture
_density>=0,_amplitude,_relief={ 0 | 1 }

            Add random mosaic texture to selected images.

-apply_channels
"command",_channels={All,RGBA,RGB,Y,CbCr,Cb,Cr,L,ab,a,b,H,S,V,K,A},_normalize={0=cut|1=normalize}

            Apply specified command on chosen normalized channels of each selected images.

-to_gray

            Force selected images to be in GRAY mode.

-to_graya

            Force selected images to be in GRAYA mode.

-to_rgb

            Force selected images to be in RGB mode.

-to_rgba

            Force selected images to be in RGBA mode.

-to_colormode
mode={0=adaptive,1=G,2=GA,3=RGB,4=RGBA}

            Force selected images to be in a given color mode.

-remove_opacity

            Remove opacity channel of selected images.

-select_color
_tolerance[%]>=0,col1,..,colN

            Select pixels with specified color in selected images.

-replace_color
_tolerance[%]>=0,_smoothness[%]>=0,src1,...,srcN,dest1,...,destN

            Replace pixels from/to specified colors in selected images.

-fill_color
col1,...,colN

            Fill selected images with specified color.

-luminance

            Compute luminance of selected images.

-mix_rgb
a11,a12,a13,a21,a22,a23,a31,a32,a33

            Apply 3x3 specified matrix to RGB colors of selected images.

-mix_channels
"(a00,...,aMN)"

            Apply specified matrix to channels of selected images.

-solarize

            Solarize selected images.

-sepia

            Apply sepia tones effect on selected images.

-split_opacity

            Split color and opacity parts of selected images.

-red_eye
0<=_threshold<=100,_smoothness>=0,0<=attenuation<=1

            Attenuate red-eye effect in selected images.

-fade_x
0<=_start<=100,0<=_end<=100

            Create horizontal fading from selected images.

-fade_y
0<=_start<=100,0<=_end<=100

            Create vertical fading from selected images.

-fade_z
0<=_start<=100,0<=_end<=100

            Create transversal fading from selected images.

-fade_radial
0<=_start<=100,0<=_end<=100

            Create radial fading from selected images.

-fade_diamond
0<=_start<=100,0<=_end<=100

            Create diamond fading from selected images.

-fade_linear
_angle,0<=_start<=100,0<=_end<=100

            Create linear fading from selected images.

-compose_rgba

            Compose selected RGBA images two-by-two, over RGB background.

-compose_average

            Compose selected images two-by-two, using average mode.

-compose_multiply

            Compose selected images two-by-two, using multiply mode.

-compose_screen

            Compose selected images two-by-two, using screen mode.

-compose_darken

            Compose selected images two-by-two, using darken mode.

-compose_lighten

            Compose selected images two-by-two, using lighten mode.

-compose_difference

            Compose selected images two-by-two, using difference mode.

-compose_negation

            Compose selected images two-by-two, using negation mode.

-compose_exclusion

            Compose selected images two-by-two, using exclusion mode.

-compose_overlay

            Compose selected images two-by-two, using overlay mode.

-compose_hardlight

            Compose selected images two-by-two, using hard light mode.

-compose_softlight

            Compose selected images two-by-two, using soft light mode.

-compose_dodge

            Compose selected images two-by-two, using dodge mode.

-compose_colorburn

            Compose selected images two-by-two, using color burn mode.

-compose_reflect

            Compose selected images two-by-two, using reflect mode.

-compose_freeze

            Compose selected images two-by-two, using freeze mode.

-compose_stamp

            Compose selected images two-by-two, using stamp mode.

-compose_interpolation

            Compose selected images two-by-two, using interpolation mode.

-compose_xor

            Compose selected images two-by-two, using xor mode.

-compose_edges
smoothness=0.8

            Compose selected images togethers using edge composition.

-compose_fade

            Compose selected images togethers using a given fading (defined as the latest image).

-compose_shapeaverage

            Compose selected images two-by-two, using shape average mode.

-cross_correlation

            Compute cross-correlation using two-by-two selected images.

-normalized_cross_correlation

            Compute normalized cross-correlation using two-by-two selected images.

-phase_correlation

            Estimate translation vector using two-by-two selected images.

-morph
nb_frames>0,_smoothness>=0,_precision>0

            Create morphing sequence between selected images.

-register_nonrigid
_smoothness>=0,_precision>0,_nb_scale>=0

            Register selected images with non-rigid warp.

-register_rigid
_smoothness>=0

            Register selected images with rigid warp.

-deinterlace
_method={ 0 | 1 }

            Deinterlace selected images ('method' can be { 0=standard or 1=motion-compensated }).

-animate
filter_name,(params_start;..;..),(params_end;..;..),nb_frames>=0,_output_frames={ 0 | 1 },_filename

            Animate filter from starting parameters to ending parameters.

-animate3d
_width>0,_height>0,_dx,_dy,_dz,_zoom>=0,_filename

            Animate selected 3d objects in a window.

-imagecube3d

            Create 3d mapped cubes from selected images.

-imagepyramid3d

            Create 3d mapped pyramides from selected images.

-text3d
"text",_font_height>0,_depth>0,_smoothness

            Create a 3d text object from specified text.

-gmic3d

            Create a 3d G'MIC logo.

-snapshot3d
_size>0,_zoom>=0

            Create 2d snapshots of selected 3d objects.
            Set 'zoom' to 0 to disable object auto-scaling.

-x_mandelbrot
_julia={ 0 | 1 },_c0r,_c0i

            Launch Mandelbrot/Julia explorer.

-x_fish_eye

            Launch fish-eye demo.

-x_spline

            Launch spline curve ditor.

-x_tictactoe

            Launch tic-tac-toe game.

-x_fourier

            Launch Fourier filtering demo.

-x_life

            Launch the Life Game.

-x_fire

            Launch fire demo.

## Examples of use

     'gmic' is a generic image processing tool which can be used in a wide variety of situations.
     Here are few examples of possible uses :

      - View a list of images :
         gmic file1.bmp file2.jpeg

      - Convert an image file :
         gmic input.bmp -o output.jpg

      - Create a volumetric image from a movie sequence :
         gmic input.mpg -a z -o output.hdr

      - Compute image gradient norm :
         gmic input.bmp -gradient_norm

      - Denoise a color image :
         gmic image.jpg -denoise 30,10 -o denoised.jpg

      - Compose two images using overlay fading :
         gmic image1.jpg image2.jpg -compose_overlay -o composed.jpg

      - Evaluate a mathematical expression :
         gmic -e "cos(pi/4)^2+sin(pi/4)^2={cos(pi/4)^2+sin(pi/4)^2}"

      - Plot a 2d function :
         gmic 1000,1,1,2 -f "X=3*(x-500)/500;X^2*sin(3*X^2)+if(c==0,u(0,-1),cos(X*10))" -plot

      - Plot a 3d elevated function in random colors:
         gmic 128,128,1,3,"?(0,255)" -plasma 10,3 -blur 4 -sharpen 10000 \
          128,128,1,1,"X=(x-64)/6;Y=(y-64)/6;100*exp(-(X^2+Y^2)/30)*abs(cos(X)*sin(Y))"\
          -elevation3d[-2] [-1] -rm[-1]

      - Plot the isosurface of a 3d volume :
         gmic -m3d 5 -md3d 5 -db3d 0 -isosurface3d "'x^2+y^2+abs(z)^abs(4*cos(x*y*z*3))'",3

      - Create a G'MIC 3d logo :
         gmic 180,70,1,3 -text G\'MIC,30,5,57,1,1 -blur 2 -n 0,100 --plasma 0.4 -+ \
          -blur 1 -elevation3d -0.1 -md3d 4

      - Create a 3d ring of torii :
         gmic -repeat 20 -torus3d 15,2 -col3d[-1] "{?(60,255)},{?(60,255)},{?(60,255)}" \
          -*3d[-1] 0.5,1 -if "{@{>,-1}%2}" -rot3d[-1] 0,1,0,90 -endif -+3d[-1] 70 -+3d \
          -rot3d 0,0,1,18 -done -md3d 3 -m3d 5 -db3d 0

      - Create a vase from a 3d isosurface :
         gmic -md3d 4 -isosurface3d "'x^2+2*abs(y/2)*sin(2*y)^2+z^2-3',0" -sphere3d 1.5 \
          --3d[-1] 0,5 -plane3d 15,15 -rot3d[-1] 1,0,0,90 -c3d[-1] -+3d[-1] 0,3.2 \
          -col3d[-1] 180,150,255 -col3d[-2] 128,255,0 -col3d[-3] 255,128,0 -+3d

      - Launch a set of G'MIC interactive demos :
         gmic -x_fish_eye -x_fire G\'MIC -x_tictactoe -rm -x_spline -x_mandelbrot 0 -x_life

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