PPMNTSC(1)PPMNTSC(1)NAMEppmntsc - Make RGB colors legal for NTSC or PAL color sys
tems.
SYNOPSISppmntsc [ --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 pix
els.
--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 ALSOppm(5), ppmdepth(1), ppmdim(1), ppmbrighten(1)AUTHOR
Wes Barris, Minnesota Supercomputer Center, Inc., Bryan
Henderson
1 April 19, 2000 PPMNTSC(1)
