ppmntsc Man page

PPMNTSC(1) General Commands Manual PPMNTSC(1)

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) sys‐
tems. 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 Stan‐
dard 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 uncor‐
rected). Output black in place of pixels that are already
legal.

–correctedonly
Output only pixels that are corrected versions of illegal pix‐
els. Output black in place of pixels that are already legal.

SEE ALSO

ppm(5), ppmdepth(1), ppmdim, ppmbrighten

AUTHOR

Wes Barris, Minnesota Supercomputer Center, Inc., Bryan Henderson

4th Berkeley Distribution April 19, 2000 PPMNTSC(1)