1img-gif(n)                            Img                           img-gif(n)
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NAME

8       img-gif - Img, Graphics Interchange Format (gif)
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SYNOPSIS

11       package require Tk
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13       package require img::gif  ?1.4?
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15       image create photo ?name? ?options?
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DESCRIPTION

20       The  package  img::gif  is  a sub-package of Img. It can be loaded as a
21       part of the complete Img support, via package require Img,  or  on  its
22       own, via package require img::gif.
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24       Like  all packages of Img it does not provide new commands, but extends
25       the existing Tk command image so  that  it  supports  files  containing
26       raster  images  in the Graphics Interchange Format (gif). More specifi‐
27       cally img::gif extends Tk's photo image type.
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29       The name of the new format handler is gif.  This handler  provides  new
30       additional  configuration options. See section GIF OPTIONS for more de‐
31       tailed explanations.
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33       All of the above means that in a call like
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35       image create photo ?name? ?options?
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37       [1]    Image data in gif format (options -data and -file)  is  detected
38              automatically.
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40       [2]    The format name gif is recognized by the option -format.  In ad‐
41              dition the value for the option is treated as list and may  con‐
42              tain any of the special options listed in section GIF OPTIONS.
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GIF OPTIONS

45       The handler provides two options, one for reading from a GIF image, the
46       other influencing the writing of such.
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48       -index n
49              This option is for reading from GIF files containing  more  than
50              one  image  (animated  GIF's, GIF movies. When specified it will
51              read the n'th image in the data. The first image is at  index  0
52              and  will be read by default, i.e. when the option is not speci‐
53              fied.
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55       -interlaced bool
56              If the value of this option is set to true  the  image  will  be
57              written  using  the interlaced sub-format of GIF. The default is
58              to write non-interlaced files. This option  is  not  implemented
59              yet.
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IMAGE COMPRESSION

62       Instead  of  LZW  the  run-length encoding of Hutchison Avenue Software
63       Corporation is used, also known as miGIF compression.  The  miGIF  com‐
64       pression  routines do not, strictly speaking, generate files conforming
65       to the GIF spec, since the image data is not  LZW-compressed  (this  is
66       the  point: in order to avoid transgression of the Unisys patent on the
67       LZW algorithm.) However, miGIF generates data streams that any  reason‐
68       ably sane LZW decompresser will decompress to what we want.
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TRANSPARENCY

71       If you want to write images to disk which contain transparency informa‐
72       tion (e.g. GIF89) you need at least Tk 8.3.
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SEE ALSO

75       img-bmp, img-dted, img-gif, img-ico, img-intro, img-jpeg, img-pcx, img-
76       pixmap,  img-png,  img-ppm, img-ps, img-raw, img-sgi, img-sun, img-tga,
77       img-tiff, img-window, img-xbm, img-xpm
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KEYWORDS

80       gif, image handling, tk
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83       Copyright (c) 1995-2009 Jan Nijtmans <nijtmans@users.sourceforge.net>
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88img-gif                               1.4                           img-gif(n)
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