1MIFF(4) Kernel Interfaces Manual MIFF(4)
2
6 MIFF - Magick Image File Format
7
9 #include <image.h>
10
12 The Magick Image File Format (MIFF) is a platform-independent format
13 for storing bitmap images. MIFF is a part of the ImageMagick toolkit
14 of image manipulation utilities for the X Window System. ImageMagick
15 is capable of converting many different image file formats to and from
16 MIFF (e.g. JPEG, XPM, TIFF, etc.).
17 A MIFF image file consist of two sections. The first section is a
19 header composed of keys describing the image in text form. The next
20 section is the binary image data. The header is separated from the
21 image data by a : character immediately followed by a newline.
22 The MIFF header is composed entirely of LATIN-1 characters. The fields
24 in the header are key and value combination in the key=value format,
25 with each key and value separated by an equal sign (=). Each key=value
26 combination is delimited by at least one control or whitespace charac‐
27 ter. Comments may appear in the header section and are always delim‐
28 ited by braces. The MIFF header always ends with a colon (:) charac‐
29 ter, followed by a ctrl-Z character. It is also common to proceed the
30 colon with a formfeed and a newline character. The formfeed prevents
31 the listing of binary data when using more(1) under Unix where the
32 ctrl-Z has the same effect with the type command on the Win32 command
33 line.
34 The following is a list of key=value combinations that may be found in
36 a MIFF file:
37 background-color=color
39 border-color=color matte-color=color these optional keys
40 reflects the image background, border, and matte colors respec‐
41 tively. A color can be a name (e.g. white) or a hex value (e.g.
42 #ccc).
43 class=DirectClass
45 class=PseudoClass the type of binary image data stored in the
46 MIFF file. If this key is not present, DirectClass image data
47 is assumed.
48 colors=value
50 the number of colors in a DirectClass image. For a PseudoClass
51 image, this key specifies the size of the colormap. If this key
52 is not present in the header, and the image is PseudoClass, a
53 linear 256 color grayscale colormap is used with the image data.
54 The maximum number of colormap entries is 65535. col‐
55 orspace=CMYK the colorspace of the pixel data. The default is
56 RGB.
57 columns=value
59 the width of the image in pixels. This is a required key and
60 has no default.
61 compression=BZip
63 compression=Fax compression=JPEG compression=LZW compression=RLE
64 compression=Zip the type of algorithm used to compress the image
65 data. If this key is not present, the image data is assumed to
66 be uncompressed.
67 delay <1/100ths of a second>
69 the interframe delay in an image sequence. The maximum delay is
70 65535.
71 depth=8
73 depth=16 the depth of a single color value representing values
74 from 0 to 255 (depth 8) or 65535 (depth 16). If this key is
75 absent, a depth of 8 is assumed.
76 dispose value
78 GIF disposal method.
79 Here are the valid methods:
81 0 No disposal specified.
83 1 Do not dispose between frames.
84 2 Overwrite frame with background color from header.
85 3 Overwrite with previous frame.
86 gamma=value
88 the gamma of the image. If it is not specified, a gamma of 1.0
89 (linear brightness response) is assumed,
90 id=ImageMagick
92 identifies the file as a MIFF-format image file. This key is
93 required and has no default. Although this key can appear any‐
94 where in the header, it should start as the first key of the
95 header in column 1. This will allow programs like file(1) to
96 easily identify the file as MIFF.
97 iterations value
99 the number of times an image sequence loops before stopping.
100 label={value}
102 defines a short title or caption for the image. If any white‐
103 space appears in the label, it must be enclosed within braces.
104 matte=True
106 matte=False specifies whether a DirectClass image has matte
107 data. Matte data is generally useful for image compositing.
108 This key has no meaning for pseudo-color images.
109 montage=<width>x<height>{+-}<x offset>{+-}<y offset>
111 size and location of the individual tiles of a composite image.
112 See X(1) for details about the geometry specification.
113 Use this key when the image is a composite of a number of dif‐
115 ferent tiles. A tile consists of an image and optionally a bor‐
116 der and a label. <width> is the size in pixels of each individ‐
117 ual tile in the horizontal direction and <height> is the size in
118 the vertical direction. Each tile must have an equal number of
119 pixels in width and equal in height. However, the width can
120 differ from the height. <x offset> is the offset in number of
121 pixels from the vertical edge of the composite image where the
122 first tile of a row begins and <y offset> is the offset from the
123 horizontal edge where the first tile of a column begins.
124 If this key is specified, a directory of tile names must follow
126 the image header. The format of the directory is explained
127 below.
128 page=value
130 preferred size and location of an image canvas.
131 profile-icc=value
133 the number of bytes in the International Color Consortium color
134 profile. The profile is defined by the ICC profile specifica‐
135 tion located at ftp://sgigate.sgi.com/pub/icc/icc34.ps.
136 colorspace=RGB
138 red-primary=x,y
140 green-primary=x,y blue-primary=x,y white-point=x,y this optional
141 key reflects the chromaticity primaries and white point.
142 rendering-intent=saturation
144 rendering-intent=perceptual rendering-intent=absolute rendering-
145 intent=relative Rendering intent is the CSS-1 property that has
146 been defined by the International Color Consortium
147 (http://www.color.org).
148 resolution=<x-resolution>x<y-resolution>
150 vertical and horizontal resolution of the image. See units for
151 the specific resolution units (e.g. pixels per inch).
152 rows=value
154 the height of the image in pixels. This is a required key and
155 has no default.
156 scene=value
158 the sequence number for this MIFF image file. This optional key
159 is used when a MIFF image file is one in a sequence of files
160 used in an animation.
161 signature=value
163 this optional key contains a string that uniquely identifies the
164 image pixel contents. NIST's SHA-256 message digest algorithm
165 is recommended.
166 units=pixels-per-inch
168 units=pixels-per-centimeter image resolution units.
169 Other key value pairs are permitted. If a value contains white‐
171 space it must be enclosed with braces as illustrated here:
172 id=ImageMagick
174 class=PseudoClass colors=256
175 compression=RunlengthEncoded packets=27601
176 columns=1280 rows=1024
177 signature=d79e1c308aa5bbcdeea8ed63df412da9
178 copyright={Copyright (c) 2001 ImageMagick Studio}
179 <FF>
180 :
181 Note that key=value combinations may be separated by newlines or spaces
184 and may occur in any order within the header. Comments (within braces)
185 may appear anywhere before the colon.
186 If you specify the montage key in the header, follow the header with a
188 directory of image tiles. This directory consists of a name for each
189 tile of the composite image separated by a newline character. The list
190 is terminated with a NULL character.
191 If you specify the color-profile key in the header, follow the header
193 (or montage directory if the montage key is in the header) with the
194 binary color profile.
195 Next comes the binary image data itself. How the image data is format‐
197 ted depends upon the class of the image as specified (or not specified)
198 by the value of the class key in the header.
199 DirectClass images (class=DirectClass) are continuous-tone, images
201 stored as RGB (red, green, blue), RGBA (red, green, blue, alpha), or
202 CMYK (cyan, yellow, magenta, black) intensity values as defined by the
203 colorspace key. Each intensity value is one byte in length for images
204 of depth 8 (0..255), whereas, images of depth 16 (0..65535) require two
205 bytes in most significant byte first order.
206 PseudoClass images (class=PseudoClass) are colormapped RGB images. The
208 colormap is stored as a series of red, green, and blue pixel values,
209 each value being a byte in size. If the image depth is 16, each col‐
210 ormap entry consumes two bytes with the most significant byte being
211 first. The number of colormap entries is defined by the colors key.
212 The colormap data occurs immediately following the header (or image
213 directory if the montage key is in the header). PseudoClass image data
214 is an array of index values into the color map. If there are 256 or
215 fewer colors in the image, each byte of image data contains an index
216 value. If the image contains more than 256 colors or the image depth is
217 16, the index value is stored as two contiguous bytes with the most
218 significant byte being first. If matte is true, each colormap index is
219 followed by a 1 or 2-byte alpha value.
220 The image data in a MIFF file may be uncompressed, runlength encoded,
222 Zip compressed, or BZip compressed. The compression key in the header
223 defines how the image data is compressed. Uncompressed pixels are just
224 stored one scanline at a time in row order. Runlength encoded compres‐
225 sion counts runs of identical adjacent pixels and stores the pixels
226 followed by a length byte (the number of identical pixels minus 1). Zip
227 and BZip compression compresses each row of an image and preceeds the
228 compressed row with the length of compressed pixel bytes as a word in
229 most significant byte first order.
230 MIFF files may contain more than one image. Simply concatenate each
232 individual image (composed of a header and image data) into one file.
233
235 display(1), animate(1), import(1), montage(1), mogrify(1), convert(1),
236 more(1), compress(1)
237
239 Copyright (C) 2000 ImageMagick Studio, a non-profit organization dedi‐
240 cated to making software imaging solutions freely available.
241 Permission is hereby granted, free of charge, to any person obtaining a
243 copy of this software and associated documentation files ("ImageMag‐
244 ick"), to deal in ImageMagick without restriction, including without
245 limitation the rights to use, copy, modify, merge, publish, distribute,
246 sublicense, and/or sell copies of ImageMagick, and to permit persons to
247 whom the ImageMagick is furnished to do so, subject to the following
248 conditions:
249 The above copyright notice and this permission notice shall be included
251 in all copies or substantial portions of ImageMagick.
252 The software is provided "as is", without warranty of any kind, express
254 or implied, including but not limited to the warranties of mer‐
255 chantability, fitness for a particular purpose and noninfringement. In
256 no event shall ImageMagick Studio be liable for any claim, damages or
257 other liability, whether in an action of contract, tort or otherwise,
258 arising from, out of or in connection with ImageMagick or the use or
259 other dealings in ImageMagick.
260 Except as contained in this notice, the name of the ImageMagick Studio
262 shall not be used in advertising or otherwise to promote the sale, use
263 or other dealings in ImageMagick without prior written authorization
264 from the ImageMagick Studio.
265
267 John Cristy, ImageMagick Studio
268ImageMagick $Date: 2007/07/21 20:09:12 $ MIFF(4)