Plan 9 from Bell Labs’s /usr/web/sources/contrib/pac/sys/doc/netpbm/ms/ppmflash.ms

Copyright © 2021 Plan 9 Foundation.
Distributed under the MIT License.
Download the Plan 9 distribution.


.TL
Ppmflash User Manual
.SH 1
ppmflash
.LP
Updated: 26 January 2003
.br
Table Of Contents
.SH 2
NAME
.LP
ppmflash - brighten a picture to approach white
.SH 2
SYNOPSIS
.LP
ppmflash 
\fIflashfactor\fR
[\fIppmfile\fR]
.SH 2
DESCRIPTION
.LP
.LP
This program is part of Netpbm.
.LP
\fBppmflash\fR 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.
.LP
\fIflashfactor\fR is a real number between 0 and 1, inclusive.
\fBppmflash\fR increases the intensity of each RGB component by the
fraction \fIflashfactor\fR 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\fR
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%.
.LP
If \fIflashfactor\fR is zero, the output is identical to the input.
If \fIflashfactor\fR is one, the output is all white.
.LP
\fBppmbrighten\fR does a more normal kind of brightening.
\fBpamfunc\fR does a very simple brightening.  Both
\fBppmbrighten\fR and \fBpamfunc\fR can reduce brightness as well.
.LP
\fBpnmgamma\fR is another way people do a similar brightening, though
it isn't really intended for that.
.SH 2
SEE ALSO
.LP
ppmbrighten
pamfunc,
pnmgamma,
ppm,
.SH 2
AUTHOR
.LP
Copyright (C) 1993 by Frank Neumann
.br
\l'5i'
.SH 2
Table Of Contents
.LP
.IP \(bu
NAME
.IP \(bu
SYNOPSIS
.IP \(bu
DESCRIPTION
.IP \(bu
SEE ALSO
.IP \(bu
AUTHOR
.LP

Bell Labs OSI certified Powered by Plan 9

(Return to Plan 9 Home Page)

Copyright © 2021 Plan 9 Foundation. All Rights Reserved.
Comments to webmaster@9p.io.