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
31       detailed 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
41              addition the value for the option is treated  as  list  and  may
42              contain  any  of  the  special  options  listed  in  section GIF
43              OPTIONS.
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GIF OPTIONS

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

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

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

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

81       gif, image handling, tk
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84       Copyright (c) 1995-2009 Jan Nijtmans <nijtmans@users.sourceforge.net>
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89img-gif                               1.4                           img-gif(n)
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