NAME¶
ppmntsc - make a portable pixmap look like taken from an American TV
SYNOPSIS¶
ppmntsc [
--pal ] [
--legalonly ] [
--illegalonly ]
[
--correctedonly ] [
--verbose ] [
--debug ] [
infile ]
Minimum unique abbreviations of options are acceptable.
DESCRIPTION¶
This program makes colors legal in the NTSC (or PAL) color systems. Often,
images generated on the computer are made for use in movies which ultimately
end up on video tape. However, the range of colors (as specified by their RGB
values) on a computer does not match the range of colors that can be
represented using the NTSC (or PAL) systems. If an image with
"illegal" colors is sent directly to an NTSC (or PAL) video system
for recording, the "illegal" colors will be clipped. This may result
in an undesirable looking picture.
This utility tests each pixel in an image to see if it falls within the legal
NTSC (or PAL) range. If not, it raises or lowers the pixel's saturation in the
output so that it does fall within legal limits. Pixels that are already OK
just go unmodified into the output.
Input is from the file named
input. If
input is
-, input is
from Standard Input. If you don't specify
input, input is from Standard
Input.
Output is always to Standard Output.
This program handles multi-image PPM input, producing multi-image PPM output.
OPTIONS¶
- --pal
- Use the PAL transform instead of the default NTSC.
- --verbose
- Print a grand total of the number of illegal pixels.
- --debug
- Produce a humongous listing of illegal colors and their
legal counterparts. NOTE: This option may produce a great deal of
output.
- --legalonly
- Output only pixels that are already legal. Output black in
place of pixels that are not.
- --illegalonly
- Output only pixels that are illegal (and output them
uncorrected). Output black in place of pixels that are already legal.
- --correctedonly
- Output only pixels that are corrected versions of illegal
pixels. Output black in place of pixels that are already legal.
SEE ALSO¶
ppm(5),
ppmdepth(1),
ppmdim(1),
ppmbrighten(1)
AUTHOR¶
Wes Barris, Minnesota Supercomputer Center, Inc., Bryan Henderson