1<?xml version="1.0" encoding="ISO-8859-1"?> 2<!DOCTYPE refentry PUBLIC 3 "-//OASIS//DTD DocBook XML V4.1.2//EN" 4 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> 5<refentry id='giftool.1'> 6<refentryinfo><date>3 June 2012</date></refentryinfo> 7<refmeta> 8<refentrytitle>giftool</refentrytitle> 9<manvolnum>1</manvolnum> 10<refmiscinfo class="source">GIFLIB</refmiscinfo> 11<refmiscinfo class="manual">GIFLIB Documentation</refmiscinfo> 12</refmeta> 13<refnamediv id='name'> 14<refname>giftool</refname> 15<refpurpose>GIF transformation tool</refpurpose> 16</refnamediv> 17 18<refsynopsisdiv id='synopsis'> 19 20<cmdsynopsis> 21 <command>giftool</command> 22 <arg choice='opt'>-a <replaceable>aspect</replaceable></arg> 23 <arg choice='opt'>-b <replaceable>bgcolor</replaceable></arg> 24 <arg choice='opt'>-d <replaceable>delaytime</replaceable></arg> 25 <arg choice='opt'>-i <replaceable>interlacing</replaceable></arg> 26 <arg choice='opt'>-n <replaceable>imagelist</replaceable></arg> 27 <arg choice='opt'>-p <replaceable>left,top</replaceable></arg> 28 <arg choice='opt'>-s <replaceable>width,height</replaceable></arg> 29 <arg choice='opt'>-t <replaceable>transcolor</replaceable></arg> 30 <arg choice='opt'>-u <replaceable>sort-flag</replaceable></arg> 31 <arg choice='opt'>-x <replaceable>disposal</replaceable></arg> 32 <arg choice='opt'>-z <replaceable>sort-flag</replaceable></arg> 33</cmdsynopsis> 34</refsynopsisdiv> 35 36<refsect1><title>Description</title> 37 38<para>A filter for transforming GIFS. With no options, it's an expensive 39copy of a GIF in standard input to standard output. Options specify 40filtering operations and are performed in the order specified on the command 41line.</para> 42 43<para>The -n option selects images, allowing the tool to act on a 44subset of images in a multi-image GIF. This option takes a 45comma-separated list of decimal integers which are interpreted as 461-origin image indices; these are the images that will be acted on. 47If no -n option is specified, the tool will select and transform all 48images.</para> 49 50<para>The -b option takes a decimal integer argument and uses it to 51set the (0-origin) screen background color index.</para> 52 53<para>The -f option accepts a printf-style format string and 54substitutes into it the values of image-descriptor and graphics-control 55fields. The string is formatted and output once for each selected 56image. Normal C-style escapes \b, \f, \n, \r, \t. \v, and \xNN are 57interpreted; also \e produces ESC (ASCII 0x1b). The following format 58cookies are substituted:</para> 59 60<variablelist> 61<varlistentry> 62<term>%a</term> 63<listitem><para>Pixel aspect byte.</para></listitem> 64</varlistentry> 65<varlistentry> 66<term>%b</term> 67<listitem><para>Screen background color.</para></listitem> 68</varlistentry> 69<varlistentry> 70<term>%d</term> 71<listitem><para>Image delay time</para></listitem> 72</varlistentry> 73<varlistentry> 74<term>%h</term> 75<listitem><para>Image height (y dimension)</para></listitem> 76</varlistentry> 77<varlistentry> 78<term>%n</term> 79<listitem><para>Image index</para></listitem> 80</varlistentry> 81<varlistentry> 82<term>%p</term> 83<listitem><para>Image position (as an x,y pair)</para></listitem> 84</varlistentry> 85<varlistentry> 86<term>%s</term> 87<listitem><para>Screen size (as an x,y pair)</para></listitem> 88</varlistentry> 89<varlistentry> 90<term>%t</term> 91<listitem><para>Image transparent-color index</para></listitem> 92</varlistentry> 93<varlistentry> 94<term>%u</term> 95<listitem><para>Image user-input flag (boolean)</para></listitem> 96</varlistentry> 97<varlistentry> 98<term>%v</term> 99<listitem><para>GIF version string</para></listitem> 100</varlistentry> 101<varlistentry> 102<term>%w</term> 103<listitem><para>Image width (x dimension)</para></listitem> 104</varlistentry> 105<varlistentry> 106<term>%x</term> 107<listitem><para>Image GIF89 disposal mode</para></listitem> 108</varlistentry> 109<varlistentry> 110<term>%z</term> 111<listitem><para>Image's color table sort flag (boolean, 112false if no local color map)</para></listitem> 113</varlistentry> 114</variablelist> 115 116<para>Boolean substitutions may take a prefix to modify how they are 117displayed:</para> 118 119<variablelist> 120<varlistentry> 121<term>1</term> 122<listitem><para>"1" or "0"</para></listitem> 123</varlistentry> 124<varlistentry> 125<term>o</term> 126<listitem><para>"on" or "off"</para></listitem> 127</varlistentry> 128<varlistentry> 129<term>t</term> 130<listitem><para>"t" or "f"</para></listitem> 131</varlistentry> 132<varlistentry> 133<term>y</term> 134<listitem><para>"yes" or "no"</para></listitem> 135</varlistentry> 136</variablelist> 137 138<para>Thus, for example, "%oz" displays image sort flags using the 139strings "on" and "off". The default with no prefix is numeric.</para> 140 141<para>The -a option takes an unsigned decimal integer argument and 142uses it to set the aspect-ratio bye in the logical screen descriptor 143block.</para> 144 145<para>The -b option takes an unsigned decimal integer argument and 146uses it to set the background color index in the logical screen 147descriptor block.</para> 148 149<para>The -d option takes a decimal integer argument and uses it to set a delay 150time, in hundredths of a second, on selected images.</para> 151 152<para>The -i option sets or clears interlaccing in selected images. Acceptable arguments are "1", "0", "yes", "no", "on", "off", "t", "f"</para> 153 154<para>The -p option takes a (0-origin) x,y coordinate-pair and sets it 155as the preferred upper-left-corner coordinates of selected 156images.</para> 157 158<para>The -s option takes a (0-origin) x,y coordinate-pair and sets it 159as the expected display screen size.</para> 160 161<para>The -t option takes a decimal integer argument and uses it to set the 162(0-origin) index of the transparency color in selected images.</para> 163 164<para>The -u option sets or clears the user-input flag in selected 165images. Acceptable arguments are "1", "0", "yes", "no", "on", "off", 166"t", "f".</para> 167 168<para>The -x option takes a decimal integer argument and uses it to set the 169GIF89 disposal mode in selected images.</para> 170 171<para>The -z option sets or clears the color-table sort flag in 172selected images. Acceptable arguments are "1", "0", "yes", "no", 173"on", "off", "t", "f".</para> 174 175<para>Note that the -a, -b, -p, -s, and -z options are included to 176complete the ability to modify all fields defined in the GIF standard, 177but should have no effect on how an image renders on browsers or 178modern viewers.</para> 179 180</refsect1> 181<refsect1><title>Author</title> 182 183<para>Eric S. Raymond.</para> 184 185</refsect1> 186</refentry> 187 188