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.\" RCSid "$Id" |
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.TH RA_PR 1 11/15/93 RADIANCE |
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.SH NAME |
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ra_pr - convert RADIANCE picture to/from pixrect rasterfile |
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.SH SYNOPSIS |
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.B ra_pr |
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[ |
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.B \-d |
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][ |
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.B \-b |
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][ |
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.B "\-c ncolors" |
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][ |
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.B "\-g gamma" |
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][ |
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.B "\-e +/-stops" |
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] |
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.B input |
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[ |
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.B output |
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] |
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.br |
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.B ra_pr |
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.B \-r |
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[ |
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.B "\-g gamma" |
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][ |
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.B "\-e +/-stops" |
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] |
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[ |
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.B input |
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[ |
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.B output |
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] |
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] |
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.SH DESCRIPTION |
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.I Ra_pr |
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converts between RADIANCE and pixrect rasterfile formats. |
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In the default mode, a RADIANCE picture is converted to a pixrect |
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rasterfile of the same horizontal and vertical dimensions with |
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8-bits per pixel. |
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The |
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.I \-d |
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option turns off dithering. |
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The |
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.I \-b |
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option converts the image to black and white, for improved quality |
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on greyscale monitors. |
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Only with this option can the input be taken from stdin. |
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The |
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.I \-c |
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option allows fewer than 256 colors. |
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The |
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.I \-g |
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option specifies the exponent used in gamma correction; |
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the default value is 2.2. |
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An exponent of 1.0 turns gamma correction off. |
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The |
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.I \-e |
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option specifies an exposure compensation in f-stops (powers of two). |
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Only integer stops are allowed, for efficiency. |
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The |
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.I \-r |
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option invokes a reverse conversion, from a pixrect rasterfile to |
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a RADIANCE picture. |
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If the output file is missing, the standard output is used. |
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.SH AUTHORS |
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Greg Ward |
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.br |
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Paul Heckbert provided the code for color quantization |
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.SH BUGS |
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Only standard 8-bit color rasterfiles are read or written. |
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.SH "SEE ALSO" |
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pfilt(1), ra_bn(1), ra_ppm(1), ra_pr24(1), ra_t8(1), ra_t16(1), |
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ra_tiff(1), ximage(1) |
