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| -rw-r--r-- | giftopnm.html | 40 | ||||
| -rw-r--r-- | ppm3d.html | 33 |
2 files changed, 51 insertions, 22 deletions
diff --git a/giftopnm.html b/giftopnm.html index 3a3d2f2e..60a2ebe9 100644 --- a/giftopnm.html +++ b/giftopnm.html @@ -2,7 +2,7 @@ <HTML><HEAD><TITLE>Giftopnm User Manual</TITLE></HEAD> <BODY> <H1>giftopnm</H1> -Updated: 6 August 2006 +Updated: 29 January 2007 <BR> <A HREF="#index">Table Of Contents</A> @@ -16,6 +16,7 @@ giftopnm - convert a GIF file into a PNM image [<B>-verbose</B>] [<B>-comments</B>] [<B>-image=</B>{<I>N</I>,<B>all</b>}] +[<B>-repair</B>] [<B>-quitearly</B>] [<I>GIFfile</I>] @@ -98,9 +99,44 @@ not do the same for the images after it; see <b>-quitearly</b>. <p>The <b>all</b> value was added in Netpbm 10.16 (June 2003). Earlier <b>giftopnm</b> can extract only one image. +<dt><b>-repair</b> + +<dd>This option makes <b>giftopnm</b> try to salvage what it can from an +invalid GIF input. + +<p>In particular, when <b>giftopnm</b> detects that the GIF input is +invalid so that it is impossible to determine what the pixels are +intended to be, it produces a single arbitrary color for all further +pixels in the image. <b>giftopnm</b> processes the image from top to +bottom, left to right, so this means the bottommost pixels will be +this padding. + +<p><b>giftopnm</b> issues warning messages when it salvages an image +in this way. + +<p>Without this option, <b>giftopnm</b> fails when it detects invalid +GIF input. Any output it produces is arbitrary, and typically is not +a valid PNM image. + +<p>It is fairly common for an image to be corrupted such that is +started off as a valid GIF, but had the end of the file cut off. An +interrupted network transfer tends to do this. In this case, +<b>giftopnm</b>'s salvage operation will produce a valid PNM image of +the proer dimensions, but with a single arbitrary color for the pixels +that were left out of the file. If the truncation is in the middle of +a row, <b>giftopnm</b> produces arbitrary pixels for the entire +truncated row. + +<p>This option was new in Netpbm 10.38 (March 2007). From 10.32 through +10.37, <b>giftopnm</b> always fails if it detects invalid GIF input. +Before 10.32, it succeeds in the case of a truncated image, and replaces +the missing pixels with arbitrary colors, not necessarily all the same +(The pre-10.32 behavior wasn't actually intended by the design). + + <dt><b>-quitearly</b> -<dd>This options makes <b>giftopnm</b> stop reading its input file as soon +<dd>This option makes <b>giftopnm</b> stop reading its input file as soon as it has converted and output the images from the input that you requested. By default, <b>giftopnm</b> reads until the end of the GIF stream, ignoring any data after the images you requested. diff --git a/ppm3d.html b/ppm3d.html index de602fc3..d329c218 100644 --- a/ppm3d.html +++ b/ppm3d.html @@ -6,30 +6,27 @@ Updated: 24 April 2004 <BR> <A HREF="#index">Table Of Contents</A> -<A NAME="lbAB"> </A> <H2>NAME</H2> -ppm3d - convert two PPM images into a red/blue 3d glasses PPM +ppm3d - convert two PPM images into an anaglyph (red/blue 3d glasses) PPM -<A NAME="lbAC"> </A> -<H2>SYNOPSIS</H2> +<H2 id="synopsis">SYNOPSIS</H2> <B>ppm3d</B> <I>leftppmfile</I> <I>rightppmfile</I> [<I>horizontal_offset</I>] -<A NAME="lbAD"> </A> -<H2>DESCRIPTION</H2> +<H2 id="description">DESCRIPTION</H2> <p>This program is part of <a href="index.html">Netpbm</a>. <p><b>ppm3d</b> reads two PPM images as input and produces a PPM as output, with the images overlapping by <I>horizontal_offset</I> pixels in blue/red format. The idea is that if you look at the image with -3-D glasses (glasses that admit only red through one eye and only green -through the other), you see an image with depth. This is called a -stereogram. +3-D glasses (glasses that admit only red through one eye and only +green or blue through the other), you see an image with depth. +This is called an anaglyph stereogram. <P><I>horizontal_offset</I> defaults to 30 pixels. The input PPMs must be the same dimensions. @@ -39,26 +36,22 @@ That makes a steregram that you view without special glasses, just by letting your eyes unfocus so that each eye sees different parts of the image. -<A NAME="lbAE"> </A> -<H2>SEE ALSO</H2> +<H2 id="seealso">SEE ALSO</H2> <A HREF="pamstereogram.html">pamstereogram</A> <A HREF="ppm.html">ppm</A> -<A NAME="lbAF"> </A> -<H2>AUTHOR</H2> +<H2 id="author">AUTHOR</H2> Copyright (C) 1993 by David K. Drum. <HR> -<A NAME="index"> </A> -<H2>Table Of Contents</H2> +<H2 id="index">Table Of Contents</H2> <UL> -<LI><A HREF="#lbAB">NAME</A> -<LI><A HREF="#lbAC">SYNOPSIS</A> -<LI><A HREF="#lbAD">DESCRIPTION</A> -<LI><A HREF="#lbAE">SEE ALSO</A> -<LI><A HREF="#lbAF">AUTHOR</A> +<LI><A HREF="#synopsis">SYNOPSIS</A> +<LI><A HREF="#description">DESCRIPTION</A> +<LI><A HREF="#seealso">SEE ALSO</A> +<LI><A HREF="#author">AUTHOR</A> </UL> </BODY> </HTML> |