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ra_rgbe - change run-length encoding of a RADIANCE picture


ra_rgbe [ -r ][ -e +/-stops ] [ input [ output ] ]


Ra_rgbe converts between RADIANCE run-length encoded and flat formats. The -e option specifies an exposure compensation in f-stops (powers of two). Only integer stops are allowed, for efficiency. By default, ra_rgbe produces a flat RADIANCE picture file from any type of RADIANCE input picture. The -r option causes ra_rgbe to produce a runlength encoded file instead. If the output file is missing, the standard output is used. If the input file is missing as well, the standard input is used.


The file format for RADIANCE pictures was changed between release 1.4 and release 2.0. The older format can still be read by all the programs, but only the newer format is produced. This newer format cannot be read by RADIANCE software prior to release 2.0.

Ra_rgbe provides some downward compatibility by producing files that can be read by older RADIANCE software. The resultant files are also easier to manipulate with programs designed to read raw raster data.

The other use for ra_rgbe is as a quicker way to adjust the exposure of a RADIANCE picture than pfilt(1), since ra_rgbe only allows integer f-stop changes. In this mode, ra_rgbe should be used with the -r option.


Greg Ward


Work on this program was initiated and sponsored by the LESO group at EPFL in Switzerland.


pfilt(1), ra_xyze(1)

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RA_RGBE(1) RADIANCE (10/16/95) RA_RGBE(1)
Page 1 (printed 7/17/96)

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