Ppmflash User Manual(1) General Commands Manual Ppmflash User Manual(1)
NAME
ppmflash - brighten a picture to approach white
SYNOPSIS
ppmflash flashfactor [ppmfile]
DESCRIPTION
This program is part of Netpbm(1).
ppmflash reads a PPM image as input. It changes the color of each pixel
to bring it a specified amount closer to white. It generates a PPM im-
age of the result.
flashfactor is a real number between 0 and 1, inclusive. ppmflash in-
creases the intensity of each RGB component by the fraction flashfactor
of the difference between the current value and full intensity. So if a
pixel contains 60% full red, 10% full green, and no blue and you specify
0.5 (half), ppmflash increases the red to 80% (because it was 40% from
full intensity, so it adds half of 40% to the original 60%), the green
to 55%, and the blue to 50%.
If flashfactor is zero, the output is identical to the input. If flash-
factor is one, the output is all white.
pambrighten does a more normal kind of brightening. pamfunc does a very
simple brightening. Both pambrighten and pamfunc can reduce brightness
as well.
pnmgamma is another way people do a similar brightening, though it isn't
really intended for that.
OPTIONS
There are no command line options defined specifically for ppmflash, but
it recognizes the options common to all programs based on libnetpbm (See
]8;;index.html#commonoptions\ Common Options]8;;\ .)
SEE ALSO
pambrighten(1) pamfunc(1), pnmgamma(1), ppm(1),
AUTHOR
Copyright (C) 1993 by Frank Neumann
DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source. The master documentation is at
http://netpbm.sourceforge.net/doc/ppmflash.html
netpbm documentation 26 January 2003 Ppmflash User Manual(1)
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