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\
.\" This man page was generated by the Netpbm tool 'makeman' from HTML source.
.\" Do not hand-hack it! If you have bug fixes or improvements, please find
.\" the corresponding HTML page on the Netpbm website, generate a patch
.\" against that, and send it to the Netpbm maintainer.
.TH "Ppmflash User Manual" 1 "26 January 2003" "netpbm documentation"
.SH NAME
ppmflash - brighten a picture to approach white
.UN synopsis
.SH SYNOPSIS
ppmflash
\fIflashfactor\fP
[\fIppmfile\fP]
.UN description
.SH DESCRIPTION
.PP
This program is part of
.BR "Netpbm" (1)\c
\&.
.PP
\fBppmflash\fP 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.
.PP
\fIflashfactor\fP is a real number between 0 and 1, inclusive.
\fBppmflash\fP increases the intensity of each RGB component by the
fraction \fIflashfactor\fP 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), \fBppmflash\fP
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%.
.PP
If \fIflashfactor\fP is zero, the output is identical to the input.
If \fIflashfactor\fP is one, the output is all white.
.PP
\fBpambrighten\fP does a more normal kind of brightening.
\fBpamfunc\fP does a very simple brightening. Both
\fBpambrighten\fP and \fBpamfunc\fP can reduce brightness as well.
.PP
\fBpnmgamma\fP is another way people do a similar brightening, though
it isn't really intended for that.
.UN options
.SH OPTIONS
.PP
There are no command line options defined specifically
for \fBppmflash\fP, but it recognizes the options common to all
programs based on libnetpbm (See
.UR index.html#commonoptions
Common Options
.UE
\&.)
.UN seealso
.SH SEE ALSO
.BR "pambrighten" (1)\c
\&
.BR "pamfunc" (1)\c
\&,
.BR "pnmgamma" (1)\c
\&,
.BR "ppm" (1)\c
\&,
.UN author
.SH AUTHOR
Copyright (C) 1993 by Frank Neumann
.SH DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source. The master documentation is at
.IP
.B http://netpbm.sourceforge.net/doc/ppmflash.html
.PP
|
