ppmflash flashfactor [ppmfile]
This program is part of Netpbm.
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 image of the result.
flashfactor is a real number between 0 and 1, inclusive. ppmflash
increases the intensity of each RGB component by the fraction flash-
factor 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
flashfactor is one, the output is all white.
ppmbrighten does a more normal kind of brightening. pamfunc does a
very simple brightening. Both ppmbrighten and pamfunc can reduce
brightness as well.
pnmgamma is another way people do a similar brightening, though it
isn't really intended for that.
ppmbrighten pamfunc, pnmgamma, ppm,
Copyright (C) 1993 by Frank Neumann
netpbm documentation 26 January 2003 Ppmflash User Manual(0)