This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles.

For more information about the manual page format, see the manual page for manpages(5).

img-gif(n)                                                                                        img-gif(n)



NAME
       img-gif - Img, Graphics Interchange Format (gif)

SYNOPSIS
       package require Tk

       package require img::gif  ?1.3?

       image create photo ?name? ?options?


DESCRIPTION
       The package img::gif is a sub-package of Img. It can be loaded as a part of the complete Img support,
       via package require Img, or on its own, via package require img::gif.

       Like all packages of Img it does not provide new commands, but extends the existing Tk command  image
       so  that  it  supports  files containing raster images in the Graphics Interchange Format (gif). More
       specifically img::gif extends Tk's photo image type.

       The name of the new format handler is  gif.   This  handler  provides  new  additional  configuration
       options. See section GIF OPTIONS for more detailed explanations.

       All of the above means that in a call like

       image create photo ?name? ?options?

       [1]    Image data in gif format (options -data and -file) is detected automatically.

       [2]    The format name gif is recognized by the option -format.  In addition the value for the option
              is treated as list and may contain any of the special options listed in section GIF OPTIONS.

GIF OPTIONS
       The handler provides two options, one for reading from a GIF image, the other influencing the writing
       of such.

       -index n
              This  option is for reading from GIF files containing more than one image (animated GIF's, GIF
              movies. When specified it will read the n'th image in the data. The first image is at index  0
              and will be read by default, i.e. when the option is not specified.

       -interlaced bool
              If the value of this option is set to true the image will be written using the interlaced sub-format subformat
              format of GIF. The default is to write non-interlaced files. This option  is  not  implemented
              yet.

IMAGE COMPRESSION
       Instead  of  LZW the run-length encoding of Hutchison Avenue Software Corporation is used, also known
       as miGIF compression. The miGIF compression routines do not, strictly speaking, generate  files  con-forming conforming
       forming  to  the GIF spec, since the image data is not LZW-compressed (this is the point: in order to
       avoid transgression of the Unisys patent on the LZW algorithm.) However, miGIF generates data streams
       that any reasonably sane LZW decompresser will decompress to what we want.

TRANSPARENCY
       If  you  want to write images to disk which contain transparency information (e.g. GIF89) you need at
       least Tk 8.3.

SEE ALSO
       img-bmp, img-gif, img-ico, img-intro, img-jpeg, img-pcx, img-pixmap, img-png, img-ppm,  img-ps,  img-sgi, imgsgi,
       sgi, img-sun, img-tga, img-tiff, img-window, img-xbm, img-xpm

KEYWORDS
       gif, image handling, tk

COPYRIGHT
       Copyright (c) 1995-2003 Jan Nijtmans <nijtmans@users.sourceforge.com>




Img                                                  1.3                                          img-gif(n)