| 1 |
greg |
1.2 |
.\" RCSid "$Id$" |
| 2 |
greg |
1.1 |
.TH RA_RGBE 1 1/23/98 RADIANCE |
| 3 |
|
|
.SH NAME |
| 4 |
|
|
ra_rgbe - convert between different RADIANCE picture types |
| 5 |
|
|
.SH SYNOPSIS |
| 6 |
|
|
.B ra_rgbe |
| 7 |
|
|
[ |
| 8 |
|
|
.B \-r |
| 9 |
|
|
][ |
| 10 |
|
|
.B "\-e +/-stops" |
| 11 |
|
|
][ |
| 12 |
|
|
.B \-f |
| 13 |
|
|
][ |
| 14 |
|
|
.B "\-n frameno" |
| 15 |
|
|
] |
| 16 |
|
|
[ |
| 17 |
|
|
.B input |
| 18 |
|
|
[ |
| 19 |
|
|
.B outspec |
| 20 |
|
|
] |
| 21 |
|
|
] |
| 22 |
|
|
.SH DESCRIPTION |
| 23 |
|
|
.I Ra_rgbe |
| 24 |
|
|
converts between RADIANCE run-length encoded and flat formats, and |
| 25 |
|
|
separates concatanated animation frames produced by |
| 26 |
|
|
.I rpict(1). |
| 27 |
|
|
The |
| 28 |
|
|
.I \-e |
| 29 |
|
|
option specifies an exposure compensation in f-stops (powers of two). |
| 30 |
|
|
Only integer stops are allowed, for efficiency. |
| 31 |
|
|
By default, |
| 32 |
|
|
.I ra_rgbe |
| 33 |
|
|
produces a flat RADIANCE picture file from any type of RADIANCE |
| 34 |
|
|
input picture. |
| 35 |
|
|
The |
| 36 |
|
|
.I \-r |
| 37 |
|
|
option causes |
| 38 |
|
|
.I ra_rgbe |
| 39 |
|
|
to produce a run-length encoded file instead. |
| 40 |
|
|
.PP |
| 41 |
|
|
If the input file consists of multiple animation frames as produced by |
| 42 |
|
|
.I rpict |
| 43 |
|
|
with the |
| 44 |
|
|
.I \-S |
| 45 |
|
|
option, |
| 46 |
|
|
.I ra_rgbe |
| 47 |
|
|
will read each frame and write it to the output file created by calling |
| 48 |
|
|
.I printf(3) |
| 49 |
|
|
with the output specification and frame number as arguments. |
| 50 |
|
|
If the output specification begins with an exclamation mark ('!'), |
| 51 |
|
|
then this interpreted as a command spec., which is also run through |
| 52 |
|
|
.I printf |
| 53 |
|
|
with the frame number to get the final command. |
| 54 |
|
|
This command must accept a Radiance picture on its standard input, |
| 55 |
|
|
and may write results either to a file or to the standard output. |
| 56 |
|
|
The |
| 57 |
|
|
.I \-n |
| 58 |
|
|
option may be used to select a specific frame for output, and |
| 59 |
|
|
other frames in the input will be skipped. |
| 60 |
|
|
Normally, all frames will be read and written. |
| 61 |
|
|
.PP |
| 62 |
|
|
.I Ra_rgbe |
| 63 |
|
|
will report an error and exit if the target output file already exists, |
| 64 |
|
|
unless the |
| 65 |
|
|
.I \-f |
| 66 |
|
|
option is given. |
| 67 |
|
|
If the output file is missing, the standard output is used. |
| 68 |
|
|
If the input file is missing or set to '-', the standard input is used. |
| 69 |
|
|
.SH NOTES |
| 70 |
|
|
The file format for RADIANCE pictures was changed between release |
| 71 |
|
|
1.4 and release 2.0. |
| 72 |
|
|
The older format can still be read by all the programs, but only |
| 73 |
|
|
the newer format is produced. |
| 74 |
|
|
This newer format cannot be read by RADIANCE software prior to |
| 75 |
|
|
release 2.0. |
| 76 |
|
|
.PP |
| 77 |
|
|
.I Ra_rgbe |
| 78 |
|
|
provides some downward compatibility by producing files that can |
| 79 |
|
|
be read by older RADIANCE software. |
| 80 |
|
|
The resultant files are also easier to manipulate with programs |
| 81 |
|
|
designed to read raw raster data. |
| 82 |
|
|
.PP |
| 83 |
|
|
The other use for |
| 84 |
|
|
.I ra_rgbe |
| 85 |
|
|
is as a quicker way to adjust the exposure of a RADIANCE picture than |
| 86 |
|
|
.I pfilt(1), |
| 87 |
|
|
since |
| 88 |
|
|
.I ra_rgbe |
| 89 |
|
|
only allows integer f-stop changes. |
| 90 |
|
|
In this mode, |
| 91 |
|
|
.I ra_rgbe |
| 92 |
|
|
should be used with the |
| 93 |
|
|
.I \-r |
| 94 |
|
|
option. |
| 95 |
|
|
.SH AUTHOR |
| 96 |
|
|
Greg Ward |
| 97 |
|
|
.SH ACKNOWLEDGEMENT |
| 98 |
|
|
Work on this program was initiated and sponsored by the LESO |
| 99 |
|
|
group at EPFL in Switzerland. |
| 100 |
|
|
.SH "SEE ALSO" |
| 101 |
|
|
pfilt(1), printf(1), ra_xyze(1), rpict(1) |
