ra_t16(1) convert RADIANCE picture to/from Targa 16 or 24-bit image file


ra_t16 [ -2 ][ -3 ][ -g gamma ][ -e +/-stops ] [ input [ output ] ]
ra_t16 -r [ -g gamma ][ -e +/-stops ] [ input [ output ] ]


Ra_t16 converts between RADIANCE and Targa 16-bit or 24-bit RGB image files (type 2 in Targa's documentation). In the default mode, a RADIANCE picture is converted to an RGB file of the same horizontal and vertical dimensions with 16-bits per pixel. The -3 option tells the program to produce a 24-bit image file instead. 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 16-bit or 24-bit Targa file to a RADIANCE picture. The determination of depth is made automatically on reverse translation, so the -2 and -3 options are not necessary. If the output file is missing, the standard output is used.


Greg Ward


Run-length encoded files can be read but not written with this program.