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 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
       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(5) ,


AUTHOR
       Copyright (C) 1993 by Frank Neumann

netpbm documentation            26 January 2003        Ppmflash User Manual(0)