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Ppmflash User Manual(0)                                Ppmflash User Manual(0)



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 image of the result.

       flashfactor is a real number between 0 and 1, inclusive.  ppmflash increases the intensity of each  RGB  compo-
       nent 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 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.


SEE ALSO
       ppmbrighten(1) pamfunc(1), pnmgamma(1), ppm(1),


AUTHOR
       Copyright (C) 1993 by Frank Neumann



netpbm documentation            26 January 2003        Ppmflash User Manual(0)