"miscellaneous update"

git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@254 9d0c8265-081b-0410-96cb-a4ca84ce46f8

3 files changed, 51 insertions, 27 deletions

diff --git a/pamtogif.html b/pamtogif.html
index 9e866c1b..30e6988a 100644
--- a/pamtogif.html
+++ b/pamtogif.html
@@ -30,6 +30,8 @@ pamtogif - convert a Netpbm image to a GIF image
 
 [<B>-nolzw</B>]
 
+[<b>-aspect=</b><i>fraction</i>]
+
 [<B>-verbose</B>]
 
 <BR>
@@ -234,6 +236,30 @@ the output of <B>pamtogif -nolzw </B>, he is then using the LZW
 patent.  But the patent holder expressed far less interest in
 enforcing the patent on decoding than on encoding.
 
+<dt><b>-aspect=</b><i>fraction</i>
+
+<dd>This is the aspect ratio of the pixels of the image.  Its only
+effect is to record that information in the GIF for use by whatever
+interprets the GIF.  Note that this feature of GIF is hardly ever used
+and most GIF decoders ignore this information and assume pixels are
+square.
+
+<p>Pixels in a Netpbm image do not have aspect ratios; there is always
+a one-one correspondence between GIF pixels and Netpbm pixels.
+
+<p>The aspect ratio is the quotient of width divided by height.  GIF
+allows aspect ratios from 0.25 (1:4) to 4 (4:1) in increments of 1/64.
+<b>pamtogif</b> implements a natural extension of GIF that allows an
+aspect ratio up to 4 14/64.  If you specify anything outside this range,
+<b>pamtogif</b> fails.  <b>pamtogif</b> rounds <i>fraction</i> to
+the nearest 1/64.
+
+<p>The default is square (1.0).
+
+<p>This option was new in Netpbm 10.38 (March 2007).  Before that, the
+pixels are always square.
+
+
 <DT><B>-verbose</B>
 
 <DD>This option causes <b>pamtogif</b> to display information about the
diff --git a/picttoppm.html b/picttoppm.html
index 9e58ec3b..c6fc07cd 100644
--- a/picttoppm.html
+++ b/picttoppm.html
@@ -35,8 +35,15 @@ picttoppm - convert a Macintosh PICT file to a PPM
 <p><b>picttoppm</b> reads a PICT file (version 1 or 2) and outputs a PPM
 image.
 
-<p>This is useful as the first step in converting a scanned image to
-something that can be displayed on Unix.
+<p>PICT is an image format that was developed by Apple Computer in
+1984 as the native format for Macintosh graphics.  A PICT image is
+encoded in QuickDraw commands.  The PICT format is a meta-format that
+can be used for both bitmap images and vector images.
+
+<p>PICT files are primarily used to exchange graphics between various
+Macintosh applications.
+
+<p>In MacOS X, PDF replaces PICT as the main graphics format.
 
 <H2 id="options">OPTIONS</H2>
 
diff --git a/ppmtopict.html b/ppmtopict.html
index 09eec70a..e6d1d5ff 100644
--- a/ppmtopict.html
+++ b/ppmtopict.html
@@ -5,37 +5,32 @@ Updated: 15 April 1990
 <BR>
 <A HREF="#index">Table Of Contents</A>
 
-<A NAME="lbAB">&nbsp;</A>
 <H2>NAME</H2>
 
 ppmtopict - convert a PPM image to a Macintosh PICT file
 
-<A NAME="lbAC">&nbsp;</A>
-<H2>SYNOPSIS</H2>
+<H2 id="synopsis">SYNOPSIS</H2>
 
 <B>ppmtopict</B>
 
 [<I>ppmfile</I>]
 
-<A NAME="lbAD">&nbsp;</A>
-<H2>DESCRIPTION</H2>
+<H2 id="description">DESCRIPTION</H2>
 
 <p>This program is part of <a href="index.html">Netpbm</a>.
 
 <p><b>ppmtopict</b> reads a PPM image as input and produces a
 Macintosh PICT file as output.
 
-<P>
-The generated file is only the data fork of a picture.  You will need
-a program such as <I>mcvert</I> to generate a Macbinary or a BinHex
-file that contains the necessary information to identify the file as a
-PICT file to MacOS.
+<P>The generated file is only the data fork of a picture.  You will
+need a program such as <I>mcvert</I> to generate a Macbinary or a
+BinHex file that contains the necessary information to identify the
+file as a PICT file to MacOS.
 
-<P>Even though PICT supports 2 and 4 bits per pixel, <b>ppmtopict</b>
+<P>Even though PICT can have 2 and 4 bits per pixel, <b>ppmtopict</b>
 always generates an 8 bits per pixel file.
 
-<A NAME="lbAE">&nbsp;</A>
-<H2>LIMITATIONS</H2>
+<H2 id="limitations">LIMITATIONS</H2>
 
 <p>The picture size field is correct only if the output is to a file
 since writing into this field requires seeking backwards on a file.
@@ -43,29 +38,25 @@ However the PICT documentation seems to suggest that this field is not
 critical anyway since it is only the lower 16 bits of the picture
 size.
 
-<A NAME="lbAF">&nbsp;</A>
-<H2>SEE ALSO</H2>
+<H2 id="seealso">SEE ALSO</H2>
 
 <A HREF="picttoppm.html">picttoppm</A>, 
 <A HREF="ppm.html">ppm</A>, 
 <b>mcvert</b>
 
-<A NAME="lbAG">&nbsp;</A>
-<H2>AUTHOR</H2>
+<H2 id="author">AUTHOR</H2>
 
 Copyright (C) 1990 by Ken Yap &lt;<A
 HREF="mailto:ken@cs.rocester.edu">ken@cs.rocester.edu</A>&gt;.
 
 <HR>
-<A NAME="index">&nbsp;</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">BUGS</A>
-<LI><A HREF="#lbAF">SEE ALSO</A>
-<LI><A HREF="#lbAG">AUTHOR</A>
+<LI><A HREF="#synopsis">SYNOPSIS</A>
+<LI><A HREF="#description">DESCRIPTION</A>
+<LI><A HREF="#limitations">LIMITATIONS</A>
+<LI><A HREF="#seealso">SEE ALSO</A>
+<LI><A HREF="#author">AUTHOR</A>
 </UL>
 </BODY>
 </HTML>