'\"
'\" Generated from file 'format-header\&.inc' by tcllib/doctools with format 'nroff'
'\" Copyright (c) 1995-2023 Jan Nijtmans <nijtmans@users\&.sourceforge\&.net>
'\"
.TH "img-gif" 3tk 1\&.4 img-gif "Img"
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.SH NAME
img-gif \- Img, Graphics Interchange Format (gif)
.SH SYNOPSIS
package require \fBTk \fR
.sp
package require \fBimg::gif  ?1\&.4?\fR
.sp
\fBimage\fR \fBcreate photo\fR ?\fIname\fR? ?\fIoptions\fR?
.sp
.BE
.SH DESCRIPTION
\fBpackage require img::gif\fR\&.
.PP
Like all packages of \fBImg\fR it does \fInot\fR provide new
commands, but extends the existing \fBTk\fR command \fBimage\fR so
that it supports files containing raster images in the
Graphics Interchange Format (gif)\&. More specifically
\fBimg::gif\fR extends \fBTk\fR's \fBphoto\fR
image type\&.
.PP
The name of the new format handler is \fBgif\fR\&.
.PP
The package \fBimg::gif\fR is a sub-package of
\fBImg\fR\&. It can be loaded as a part of the complete Img support,
via \fBpackage require Img\fR, or on its own, via
\fBpackage require img::gif\fR\&.
.PP
This handler provides new additional configuration options\&. See
section \fBGIF OPTIONS\fR for more detailed explanations\&.
.PP
All of the above means that in a call like
.TP
\fBimage\fR \fBcreate photo\fR ?\fIname\fR? ?\fIoptions\fR?
.PP
.IP [1]
Image data in gif format (options \fB-data\fR and \fB-file\fR) is
detected automatically\&.
.IP [2]
The format name \fBgif\fR is recognized by the option \fB-format\fR\&.
In addition the value for the option is treated as list and may
contain any of the special options listed in section
\fBGIF OPTIONS\fR\&.
.PP
.SH "GIF OPTIONS"
The handler provides the following options:
.TP
\fB-index\fR \fIn\fR
This option is for reading from GIF files containing more than one
image (\fIanimated GIF's\fR, \fIGIF movies\fR)\&. When specified, it
will read the \fIn\fR'th image in the data\&. The first image is at
index \fB0\fR and will be read by default, i\&.e\&. when the option is
not specified\&.
.PP
.SH "IMAGE COMPRESSION"
Instead of LZW the run-length encoding of Hutchison Avenue Software
Corporation is used, also known as \fImiGIF\fR compression\&. The miGIF
compression routines do not, strictly speaking, generate files
conforming 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\&.
.SH TRANSPARENCY
If you want to write images to disk which contain transparency
information (e\&.g\&. GIF89) you need at least \fBTk\fR 8\&.3\&.
.PP
.SH "SEE ALSO"
img-bmp, img-dted, img-flir, img-gif, img-ico, img-intro, img-jpeg, img-pcx, img-pixmap, img-png, img-ppm, img-ps, img-raw, img-sgi, img-sun, img-tga, img-tiff, img-window, img-xbm, img-xpm
.SH KEYWORDS
gif, image handling, tk
.SH COPYRIGHT
.nf
Copyright (c) 1995-2023 Jan Nijtmans <nijtmans@users\&.sourceforge\&.net>

.fi