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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 image 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
       flashfactor 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
        Common Options ⟨index.html#commonoptions⟩ .)

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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