rawtopgm (1)
convert raw grayscale bytes into a portable graymap
SYNOPSIS
rawtopgm
[ -headerskip
N ]
[ -rowskip
N ]
[ -tb | -topbottom ]
[ width
height ]
[ imagedata ]
DESCRIPTION
Reads raw grayscale bytes as input.
"raw grayscale"
Produces a portable graymap as output.
The input file is just grayscale bytes.
If you don't specify the width and height on the command line,
the program will check the size of the image and try to make
a quadratic image of it. It is an error to supply a non
quadratic image without specifying width and height.
The maxval is assumed to be 255.
OPTIONS
-headerskip
If the file has a header, you can use this flag to
skip over it.
-rowskip
If there is padding at the ends of the rows, you can skip it with this flag.
Note that rowskip can be a real number.
Amazingly, I once had an image with 0.376 bytes of padding per row.
This turned out to be due to a file-transfer problem, but I was still
able to read the image.
-tb -topbottom
Flips the image upside down.
The first pixel in a pgm file is in the lower left corner of the image.
For conversion from images with the first pixel in the upper left corner
(e.g. the Molecular Dynamics and Leica confocal formats) this flips the
image right.
This is equivalent to
rawtopgm [file] | pnmflip -tb
BUGS
If you don't specify the image width and height, the program will
try to read the entire image to a memory buffer. If you get a
message that states that you are out of memory, try to specify the width
and height on the command line. Also, the -tb option consumes much
memory.
SEE ALSO
AUTHORS
Copyright (C) 1989 by Jef Poskanzer.
Modified June 1993 by Oliver Trepte, oliver@fysik4.kth.se
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