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

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

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

17       The  package  img::gif  is  a sub-package of Img. It can be loaded as a
18       part of the complete Img support, via package require Img,  or  on  its
19       own, via package require img::gif.
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21       Like  all packages of Img it does not provide new commands, but extends
22       the existing Tk command image so  that  it  supports  files  containing
23       raster  images  in the Graphics Interchange Format (gif). More specifi‐
24       cally img::gif extends Tk's photo image type.
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26       The name of the new format handler is gif.  This handler  provides  new
27       additional  configuration  options.  See  section  GIF OPTIONS for more
28       detailed explanations.
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30       All of the above means that in a call like
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32       image create photo ?name? ?options?
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34       [1]    Image data in gif format (options -data and -file)  is  detected
35              automatically.
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37       [2]    The  format  name  gif  is recognized by the option -format.  In
38              addition the value for the option is treated  as  list  and  may
39              contain  any  of  the  special  options  listed  in  section GIF
40              OPTIONS.
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GIF OPTIONS

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

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

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

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

78       gif, image handling, tk
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81       Copyright (c) 1995-2009 Jan Nijtmans <nijtmans@users.sourceforge.net>
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86img-gif                               1.4                           img-gif(n)
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