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<A NAME="PAGENUM-368"><P>Page 368</P></A>
<P><B>
AUTHORS
</B>
</P>
<P>Copyright " 1988 by James Darrell McCauley
(jdm5548@diamond.tamu.edu) and Jef Poskanzer.
</P>
<P>2 November 1990
</P>
<H3><A NAME="ch01_ 236">
pbmupc
</A></H3>
<P>pbmupc—Create a Universal Product Code bitmap
</P>
<P><B>
SYNOPSIS
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
pbmupc [-s1|-s2] type manufac product
</PRE>
<!-- END CODE SNIP //-->
<P><B>
DESCRIPTION
</B>
</P>
<P>pbmupc generates a Universal Product Code symbol. The three arguments are: a one-digit product type, a five-digit
manufacturer code, and a five-digit product code. For example,
0 72890 00011 is the code for Heineken.
</P>
<P>As presently configured, pbmupc produces a bitmap 230 bits wide and 175 bits high. The size can be altered by changing
the defines at the beginning of the program, or by running the output through
pnmenlarge or pnmscale.
</P>
<P><B>
OPTIONS
</B>
</P>
<P>The -s1 and -s2 flags select the style of UPC to generate. The default,
-s1, looks more or less like this:</P>
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<PRE>
||||||||||||||||
||||||||||||||||
||||||||||||||||
||||||||||||||||
0||12345||67890||5
</PRE>
<!-- END CODE SNIP //-->
<P>The other style, -s2, puts the product type digit higher up, and doesn't display the
checksum digit:</P>
<!-- CODE SNIP //-->
<PRE>
||||||||||||||||
||||||||||||||||
0|||||||||||||||
||||||||||||||||
||12345||67890||
</PRE>
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<P><B>
SEE ALSO
</B>
</P>
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<PRE>pbm(5)
</PRE>
<!-- END CODE SNIP //-->
<P><B>
AUTHOR
</B>
</P>
<P>Copyright " 1989 by Jef Poskanzer.
</P>
<P>14 March 1989
</P>
<H3><A NAME="ch01_ 237">
pcxtoppm
</A></H3>
<P>pcxtoppm—Convert a PCX file into a portable pixmap
</P>
<P><B>
SYNOPSIS
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
pcxtoppm[pcxfile]
</PRE>
<!-- END CODE SNIP //-->
<P><B>
DESCRIPTION
</B>
</P>
<P>pcxtoppm reads a PCX file as input and produces a portable pixmap as output.
</P>
<A NAME="PAGENUM-369"><P>Page 369</P></A>
<P><B>
SEE ALSO
</B></P>
<!-- CODE SNIP //-->
<PRE>ppmtopcx(1), ppm(5)
</PRE>
<!-- END CODE SNIP //-->
<P><B>
AUTHOR
</B>
</P>
<P>Copyright " 1990 by Michael Davidson.
</P>
<P>9 April 1990
</P>
<H3><A NAME="ch01_ 238">
pfbtops
</A></H3>
<P>pfbtops—Translate a PostScript font in PFB format to ASCII
</P>
<P><B>
SYNOPSIS
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
pfbtops [ pfb_file ]
</PRE>
<!-- END CODE SNIP //-->
<P><B>
DESCRIPTION
</B>
</P>
<P>pfbtops translates a PostScript font in PFB format to ASCII. If
pfb_file is omitted, the PFB file will be read from
the standard input. The ASCII format PostScript font will be written on the standard output. PostScript fonts for MS-DOS
are normally supplied in PFB format.
</P>
<P>The resulting ASCII format PostScript font can be used with
groff. It must first be listed in
/usr/lib/groff/font/devps/download.
</P>
<P><B>
SEE ALSO
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
grops(1)
</PRE>
<!-- END CODE SNIP //-->
<P>Groff Version 1.09, 6 August 1992
</P>
<H3><A NAME="ch01_ 239">
pgmbentley
</A></H3>
<P>pgmbentley—Bentleyize a portable graymap
</P>
<P><B>
SYNOPSIS
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
pgmbentley [pgmfile]
</PRE>
<!-- END CODE SNIP //-->
<P><B>
DESCRIPTION
</B>
</P>
<P>pgmbentley reads a portable graymap as input, performs the Bentley Effect, and writes a portable graymap as output.
</P>
<P>The Bentley Effect is described in Beyond
Photography by Holzmann, Chapter 4, photo 4. It's a vertical smearing based
on brightness.
</P>
<P><B>
SEE ALSO
</B>
</P>
<!-- CODE SNIP //-->
<PRE>pgmoil(1), ppmrelief(1), pgm(5)
</PRE>
<!-- END CODE SNIP //-->
<P><B>
AUTHOR
</B>
</P>
<P>Copyright " 1990 by Wilson Bent
(whb@hoh-2.att.com).
</P>
<P>11 January 1991
</P>
<A NAME="PAGENUM-370"><P>Page 370</P></A>
<H3><A NAME="ch01_ 240">
pgmcrater
</A></H3>
<P>pgmcrater—Create cratered terrain by fractal forgery
</P>
<P><B>
SYNOPSIS
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
pgmcrater [-number n][-height|-ysize s][-width|-xsize s][-gamma g]
</PRE>
<!-- END CODE SNIP //-->
<P><B>
DESCRIPTION
</B>
</P>
<P>pgmcrater creates a portable graymap that mimics cratered terrain. The graymap is created by simulating the impact of
a given number of craters with random position and size, then rendering the resulting terrain elevations based on a light
source shining from one side of the screen. The size distribution of the craters is based on a power law that results in many
more small craters than large ones. The number of craters of a given size varies as the reciprocal of the area as described on pages
31 and 32 of The Science Of Fractal Images, edited by H.O. Peitgen and D. Saupe (New York: Springer-Verlag, 1988).
Cratered bodies in the solar system are observed to obey this relationship. The formula used to obtain crater radii governed by this
law from a uniformly distributed pseudorandom sequence was developed by Rudy Rucker.
</P>
<P>High resolution images with large numbers of craters often benefit from being piped through
pnmsmooth. The averaging performed by this process eliminates some of the jagged pixels and lends a mellow "telescopic image" feel to the
overall picture.
</P>
<P><B>
OPTIONS
</B>
</P>
<P>-number n Causes n craters to be generated. If no
-number specification is given, 50,000 craters will be generated.
Don't expect to see them all! For every large crater, there are many, many more tiny ones that tend simply to erode the
landscape. In general, the more craters you specify, the more realistic the result; ideally, you want the entire terrain to have
been extensively turned over again and again by cratering. High-resolution images containing five to ten million craters
are stunning but take quite a while to create.
</P>
<TABLE>
<TR><TD>
-height
</TD><TD>
height
</TD><TD>
Sets the height of the generated image to
height pixels. The default height is 256 pixels.
</TD></TR><TR><TD>
-width
</TD><TD>
width
</TD><TD>
Sets the width of the generated image to
width pixels. The default width is 256 pixels.
</TD></TR><TR><TD>
-xsize
</TD><TD>
width
</TD><TD>
Sets the width of the generated image to
width pixels. The default width is 256 pixels.
</TD></TR><TR><TD>
-ysize
</TD><TD>
height
</TD><TD>
Sets the height of the generated image to
height pixels. The default height is 256 pixels.
</TD></TR><TR><TD>
-gamma
</TD><TD>
factor
</TD><TD>
The specified factor is used to gamma correct the graymap in the same manner as performed by
pnmgamma. The default value is 1.0, which results in a medium contrast image. Values larger than 1 lighten the
image and reduce contrast, while values less than 1 darken the image, increasing contrast.
</TD></TR></TABLE>
<P>All flags can be abbreviated to their shortest unique prefix.
</P>
<P><B>
BUGS
</B>
</P>
<P>The -gamma option isn't really necessary because you can achieve the same effect by piping the output from
pgmcrater through pnmgamma. However, pgmcrater performs an internal gamma map anyway in the process of rendering the
elevation array into a graymap, so there's no additional overhead in allowing a user-specified gamma.
</P>
<P>Real craters have two distinct morphologies. pgmcrater
simulates only small craters, which are hemispherical in
shape (regardless of the incidence angle of the impacting body, as long as the velocity is sufficiently high). Large craters, such
as Copernicus and Tycho on the moon, have a "walled plain" shape with a cross-section more like:
</P>
<!-- CODE SNIP //-->
<PRE>
/\/\
_____/ \_____ /\______/ \______
</PRE>
<!-- END CODE SNIP //-->
<P>Larger craters should really use this profile, including the central peak, and totally obliterate the preexisting terrain.
</P>
<P><B>
SEE ALSO
</B>
</P>
<!-- CODE SNIP //-->
<PRE>
pgm(5), pnmgamma(1), pnmsmooth(1)
</PRE>
<!-- END CODE SNIP //-->
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