Computer Science
asciitopgm(1) asciitopgm(1)
NAME
asciitopgm - convert ASCII graphics into a portable
graymap
SYNOPSIS
asciitopgm [-d divisor] height width [asciifile]
DESCRIPTION
Reads ASCII data as input. Produces a portable graymap
with pixel values which are an approximation of the
"brightness" of the ASCII characters, assuming black-on-
white printing. In other words, a capital M is very dark,
a period is ver light, and a space is white. Input lines
which are fewer than width characters are automatically
padded with spaces.
The divisor argument is a floating-point number by which
the output pixels are divided; the default value is 1.0.
This can be used to adjust the brightness of the graymap:
for example, if the image is too dim, reduce the divisor.
In keeping with (I believe) Fortran line-printer conven-
tions, input lines beginning with a + (plus) character are
assumed to "overstrike" the previous line, allowing a
larger range of gray values.
This tool contradicts the message in the pbmtoascii man-
ual: "Note that there is no asciitopbm tool - this trans-
formation is one-way."
BUGS
The table of ASCII-to-grey values is subject to interpre-
tation, and, of course, depends on the typeface intended
for the input.
SEE ALSO
pbmtoascii(1), pgm(5)
AUTHOR
Wilson H. Bent. Jr. (whb@usc.edu)
26 December 1994 1
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