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NAME
MIFF - Magick Image File Format is a platform-independent
format for storing bitmap images. MIFF is a part of the
ImageMagick toolkit of image manipulation utilities for the
X Window System. ImageMagick is capable of converting many
different image file formats to and from MIFF (e.g. JPEG,
XPM, TIFF, etc.).
SYNOPSIS
#include <image.h>
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 character. Comments
may appear in the header section and are always delimited by
braces. The MIFF header always ends with a colon (:)
character, 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 respectively. 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.
colorspace=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=RunlengthEncoded 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 <1/100ths of a second>
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 anywhere 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
whitespace 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=<width>x<height>{+-}<x offset>{+-}<y offset>
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 different tiles. A tile consists of an image and
optionally a border and a label. <width> is the size
in pixels of each individual tile in the horizontal
direction and <height> 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. <x offset> is the
offset in number of pixels from the vertical edge of
the composite image where the first tile of a row
begins and <y offset> 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 specification 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=<x-resolution>x<y-resolution>
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. RSA's Data
Security MD5 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 whitespace 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) 2000 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 formatted 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 colormap 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 compression 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
Copyright (C) 2000 ImageMagick Studio, a non-profit
organization dedicated to making software imaging solutions
freely available.
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated
documentation files ("ImageMagick"), to deal in ImageMagick
without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of ImageMagick, and to permit
persons to whom the ImageMagick is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall
be included in all copies or substantial portions of
ImageMagick.
The software is provided "as is", without warranty of any
kind, express or implied, including but not limited to the
warranties of merchantability, fitness for a particular
purpose and noninfringement. In no event shall ImageMagick
Studio be liable for any claim, damages or other liability,
whether in an action of contract, tort or otherwise, arising
from, out of or in connection with ImageMagick or the use or
other dealings in ImageMagick.
Except as contained in this notice, the name of the
ImageMagick Studio shall not be used in advertising or
otherwise to promote the sale, use or other dealings in
ImageMagick without prior written authorization from the
ImageMagick Studio.
AUTHORS
John Cristy, ImageMagick Studio
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