Asciitopgm User Manual(0) Asciitopgm User Manual(0)NAMEasciitopgm - convert ASCII graphics into a PGM
SYNOPSISasciitopgm [-d divisor] height width [asciifile]
DESCRIPTION
This program is part of Netpbm(1)asciitopgm reads ASCII data as input and produces a PGM image 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 very light, and a space is white.
Obviously, asciitopgm assumes a certain font in assigning a brightness
value to a character.
asciitopgm considers ASCII control characters to be all white. For a
lower case character, It assigns a special brightnesses which has noth‐
ing to do with what it looks like printed. asciitopgm takes the ASCII
character code from the lower 7 bits of each input byte. But it warns
you if the most significant bit of any input byte is not zero.
The output image is height pixels high by width pixels wide, truncating
and padding with white on the right and bottom as necessary.
The divisor value is an integer (decimal) by which the blackness of an
input character is divided; the default value is 1. You can use this
to adjust the brightness of the output: for example, if the image is
too bright, increase the divisor.
In a sort of reminiscence of Fortran line printer carriage control,
where a line starts with + (plus), asciitopgm combines it with the pre‐
vious row of output instead of generating a new row. This allows a
larger range of gray values. (In Fortran carriage control, the first
character of every line sent to the printer tells how much to advance
the paper, with + meaning not at all, so that the rest of the charac‐
ters on the line overstrike the ones already on the paper. What asci‐
itopgm does is rather different in that asciitopgm does not reserve the
first character of every line that way. If the first character is any‐
thing but +, asciitopgm considers it just to be first character of the
image.
If you're looking for something that creates an image of text, with
that text specified in ASCII, that is something quite different. Use
pbmtext for that.
SEE ALSOpbmtoascii(1) , pbmtext(1) , pgm(5)AUTHOR
Wilson H. Bent. Jr. (whb@usc.edu)
netpbm documentation 20 January 2011 Asciitopgm User Manual(0)
