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ra_pr (1)
NAME
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ra_pr - convert RADIANCE picture to/from pixrect rasterfile |
SYNOPSIS
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ra_pr [ -d ][ -b ][ -c ncolors
][ -g gamma ][ -e +/-stops ] input [
output ]
ra_pr -r [ -g gamma ][ -e +/-stops ] [
input [ output ] ] |
DESCRIPTION
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Ra_pr converts between RADIANCE and pixrect
rasterfile formats. In the default mode, a RADIANCE picture
is converted to a pixrect rasterfile of the same horizontal
and vertical dimensions with 8-bits per pixel. The -d
option turns off dithering. The -b option converts
the image to black and white, for improved quality on
greyscale monitors. Only with this option can the input be
taken from stdin. The -c option allows fewer than 256
colors. The -g option specifies the exponent used in
gamma correction; the default value is 2.2. An exponent of
1.0 turns gamma correction off. The -e option
specifies an exposure compensation in f-stops (powers of
two). Only integer stops are allowed, for efficiency. The
-r option invokes a reverse conversion, from a
pixrect rasterfile to a RADIANCE picture. If the output file
is missing, the standard output is used. |
AUTHORS
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Greg Ward
Paul Heckbert provided the code for color
quantization |
BUGS
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Only standard 8-bit color rasterfiles are read or
written. |
SEE ALSO
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