unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (Debian-3.1)
Page:
Section:
Apropos / Subsearch:
optional field

MIFF(4)                    Kernel Interfaces Manual                    MIFF(4)



NAME
       MIFF - Magick Image File Format is a platform-independent format for
       storing bitmap images.

SYNOPSIS
       #include <&lt;image.h>&gt;

DESCRIPTION
       A MIFF image file consist of two sections.  The first section is a
       header composed of keys describing the image in text form.  The next
       section is the binary image data.  The header is separated from the
       image data by a : character immediately followed by a newline.

       The MIFF header is composed entirely of LATIN-1 characters.  The fields
       in the header are key and value combination in the key=value format,
       with each key and value separated by an equal sign (=).  Each key=value
       combination is delimited by at least one control or whitespace charac-
       ter.  Comments may appear in the header section and are always delim-
       ited by braces.  The MIFF header always ends with a colon (:) charac-
       ter, followed by a ctrl-Z character.  It is also common to proceed the
       colon with a formfeed and a newline character.  The formfeed prevents
       the listing of binary data when using more(1) under Unix where the
       ctrl-Z has the same effect with the type command on the Win32 command
       line.

       The following is a list of key=value combinations that may be found in
       a MIFF file:

       background-color=color
              border-color=color matte-color=color these optional keys
              reflects the image background, border, and matte colors respec-
              tively. A color can be a name (e.g. white) or a hex value (e.g.
              #ccc).

       class=DirectClass
              class=PseudoClass the type of binary image data stored in the
              MIFF file.  If this key is not present, DirectClass image data
              is assumed.

       colors=value
              the number of colors in a DirectClass image. For a PseudoClass
              image, this key specifies the size of the colormap.  If this key
              is not present in the header, and the image is PseudoClass, a
              linear 256 color grayscale colormap is used with the image data.
              The maximum number of colormap entries is 65535.  col-
              orspace=CMYK the colorspace of the pixel data.  The default is
              RGB.

       columns=value
              the width of the image in pixels.  This is a required key and
              has no default.

       compression=BZip
              compression=Fax compression=JPEG compression=LZW compression=RLE
              compression=Zip the type of algorithm used to compress the image
              data.  If this key is not present, the image data is assumed to
              be uncompressed.

       delay &lt;1/100ths of a second&gt;
              the interframe delay in an image sequence.  The maximum delay is
              65535.

       depth=8
              depth=16 the depth of a single color value representing values
              from 0 to 255 (depth 8) or 65535 (depth 16).  If this key is
              absent, a depth of 8 is assumed.

       dispose value
              GIF disposal method.

              Here are the valid methods:

                   0  No disposal specified.
                   1  Do not dispose between frames.
                   2  Overwrite frame with background color from header.
                   3  Overwrite with previous frame.

       gamma=value
              the gamma of the image.  If it is not specified, a gamma of 1.0
              (linear brightness response) is assumed,

       id=ImageMagick
              identifies the file as a MIFF-format image file.  This key is
              required and has no default.  Although this key can appear any-
              where in the header, it should start as the first key of the
              header in column 1.  This will allow programs like file(1) to
              easily identify the file as MIFF.

       iterations value
              the number of times an image sequence loops before stopping.

       label={value}
              defines a short title or caption for the image.  If any white-
              space appears in the label, it must be enclosed within braces.

       matte=True
              matte=False specifies whether a DirectClass image has matte
              data.  Matte data is generally useful for image compositing.
              This key has no meaning for pseudo-color images.

       montage=&lt;width&gt;x&lt;height&gt;{+-}&lt;x offset&gt;{+-}&lt;y offset&gt;
              size and location of the individual tiles of a composite image.
              See X(1) for details about the geometry specification.

              Use this key when the image is a composite of a number of dif-
              ferent tiles.  A tile consists of an image and optionally a bor-
              der and a label.  &lt;width&gt; is the size in pixels of each individ-
              ual tile in the horizontal direction and &lt;height&gt; is the size in
              the vertical direction.  Each tile must have an equal number of
              pixels in width and equal in height.  However, the width can
              differ from the height.  &lt;x offset&gt; is the offset in number of
              pixels from the vertical edge of the composite image where the
              first tile of a row begins and &lt;y offset&gt; is the offset from the
              horizontal edge where the first tile of a column begins.

              If this key is specified, a directory of tile names must follow
              the image header.  The format of the directory is explained
              below.

       page=value
              preferred size and location of an image canvas.

       profile-icc=value
              the number of bytes in the International Color Consortium color
              profile.  The profile is defined by the ICC profile specifica-
              tion located at ftp://sgigate.sgi.com/pub/icc/icc34.ps.

       colorspace=RGB

       red-primary=x,y
              green-primary=x,y blue-primary=x,y white-point=x,y this optional
              key reflects the chromaticity primaries and white point.

       rendering-intent=saturation
              rendering-intent=perceptual rendering-intent=absolute rendering-
              intent=relative Rendering intent is the CSS-1 property that has
              been defined by the International Color Consortium
              (http://www.color.org).

       resolution=&lt;x-resolution&gt;x&lt;y-resolution&gt;
              vertical and horizontal resolution of the image.  See units for
              the specific resolution units (e.g. pixels per inch).

       rows=value
              the height of the image in pixels.  This is a required key and
              has no default.

       scene=value
              the sequence number for this MIFF image file.  This optional key
              is used when a MIFF image file is one in a sequence of files
              used in an animation.

       signature=value
              this optional key contains a string that uniquely identifies the
              image pixel contents.  NIST's SHA-256 message digest algorithm
              is recommended.

       units=pixels-per-inch
              units=pixels-per-centimeter image resolution units.

              Other key value pairs are permitted.  If a value contains white-
              space it must be enclosed with braces as illustrated here:

                  id=ImageMagick
                  class=PseudoClass  colors=256
                  compression=RunlengthEncoded  packets=27601
                  columns=1280  rows=1024
                  signature=d79e1c308aa5bbcdeea8ed63df412da9
                  copyright={Copyright (c) 2001 ImageMagick Studio}
                  <FF>
                  :


       Note that key=value combinations may be separated by newlines or spaces
       and may occur in any order within the header.  Comments (within braces)
       may appear anywhere before the colon.

       If you specify the montage key in the header, follow the header with a
       directory of image tiles.  This directory consists of a name for each
       tile of the composite image separated by a newline character.  The list
       is terminated with a NULL character.

       If you specify the color-profile key in the header, follow the header
       (or montage directory if the montage key is in the header) with the
       binary color profile.

       Next comes the binary image data itself.  How the image data is format-
       ted depends upon the class of the image as specified (or not specified)
       by the value of the class key in the header.

       DirectClass images (class=DirectClass) are continuous-tone, images
       stored as RGB (red, green, blue), RGBA (red, green, blue, alpha), or
       CMYK (cyan, yellow, magenta, black) intensity values as defined by the
       colorspace key. Each intensity value is one byte in length for images
       of depth 8 (0..255), whereas, images of depth 16 (0..65535) require two
       bytes in most significant byte first order.

       PseudoClass images (class=PseudoClass) are colormapped RGB images. The
       colormap is stored as a series of red, green, and blue pixel values,
       each value being a byte in size. If the image depth is 16, each col-
       ormap entry consumes two bytes with the most significant byte being
       first. The number of colormap entries is defined by the colors key.
       The colormap data occurs immediately following the header (or image
       directory if the montage key is in the header). PseudoClass image data
       is an array of index values into the color map. If there are 256 or
       fewer colors in the image, each byte of image data contains an index
       value. If the image contains more than 256 colors or the image depth is
       16, the index value is stored as two contiguous bytes with the most
       significant byte being first. If matte is true, each colormap index is
       followed by a 1 or 2-byte alpha value.

       The image data in a MIFF file may be uncompressed, runlength encoded,
       Zip compressed, or BZip compressed. The compression key in the header
       defines how the image data is compressed. Uncompressed pixels are just
       stored one scanline at a time in row order. Runlength encoded compres-
       sion counts runs of identical adjacent pixels and stores the pixels
       followed by a length byte (the number of identical pixels minus 1). Zip
       and BZip compression compresses each row of an image and preceeds the
       compressed row with the length of compressed pixel bytes as a word in
       most significant byte first order.

       MIFF files may contain more than one image.  Simply concatenate each
       individual image (composed of a header and image data) into one file.

SEE ALSO
       display(1), animate(1), import(1), montage(1), mogrify(1), convert(1),
       more(1), compress(1)

COPYRIGHT
       See http://www.imagemagick.org/www/Copyright.html

AUTHORS
       John Cristy, ImageMagick Studio



ImageMagick              $Date: 2004/08/30 01:12:25 $                  MIFF(4)