man/man1/ra_tiff.1

.\" SCCSid "@(#)ra_tiff.1 2.3 8/29/97 LBL"
.TH RA_TIFF 1 8/29/97 RADIANCE
.SH NAME
ra_tiff - convert RADIANCE picture to/from a TIFF color or greyscale image
.SH SYNOPSIS
.B ra_tiff
[
.B "-z|-L|-l|-f|-w"
][
.B -b
][
.B "-e +/-stops"
][
.B "-g gamma"
]
{
.B "in.hdr|-"
}
.B out.tif
.br
.B "ra_tiff -r"
[
.B \-x
][
.B "\-g gamma"
][
.B "\-e +/-stops"
]
.B in.tif
[
.B "out.hdr|-"
]
.SH DESCRIPTION
.I Ra_tiff
converts between RADIANCE and TIFF image formats.
The
.I \-g
option specifies the exponent used in gamma correction;
the default value is 2.2, which is the recommended value
for TIFF images.
.PP
The
.I \-b
option can be used to specify an 8-bit greyscale TIFF output file.
The type of input file is determined automatically.
.PP
The
.I \-z
option will result in LZW compression of the TIFF output file.
The
.I \-L
option specifies SGILOG compression, which is recommended
to capture the full dynamic range of the Radiance picture.
However, since many TIFF readers do not yet support this format,
use this option under advisement.
The
.I \-l
option specifies SGILOG24 compressed output, which has
less dynamic range than SGILOG, but may be smaller in some cases.
(It is usually larger.)\0
The
.I \-f
option specifies 32-bit IEEE floating-point/primary output, which
is the highest resolution format but results in very large files, since
each RGB pixel takes 96 bits (12 bytes) and does not compress well.
The
.I \-w
option specifies 16-bit/primary output, which is understood by
some photo editing software, such as Adobe Photoshop.
Decompression is automatically determined for TIFF input.
.PP
The
.I \-e
option specifies an exposure compensation in f-stops (powers of two).
Only integer stops are allowed, for efficiency.
.PP
If the Radiance input is a hyperspectral picture, it will be
converted accurately if the output is anything but 24-bit RGB.
In the latter case, the converted colors will be approximate.
.PP
The
.I \-r
option invokes a reverse conversion, from a TIFF image to
a RADIANCE picture.
The RADIANCE picture file can be taken from the standard input
or sent to the standard output by using a hyphen ('-') in place
of the file name, but the TIFF image must be to or from a file.
The
.I \-x
option can be used to specify an XYZE Radiance output file, rather
than the default RGBE.
.SH EXAMPLES
To convert a Radiance picture to SGILOG-compressed TIFF format:
.IP "" .2i
ra_tiff \-L scene1.hdr scene1.tif
.PP
To later convert this image back into Radiance and display using
human visibility tone-mapping:
.IP "" .2i
ra_tiff \-r scene1.tif scene1.hdr
.br
ximage \-e human scene1.hdr
.SH AUTHOR
Greg Ward
.br
Sam Leffler
.SH ACKNOWLEDGEMENT
Work on this program was initiated and sponsored by the LESO
group at EPFL in Switzerland.
Additions for the SGILOG data encoding were sponsored by Silicon Graphics, Inc.
.SH BUGS
Many TIFF file subtypes are not supported.
.br
A gamma value other than 2.2 is not properly recorded or understood if
recorded in the TIFF file.
.SH "SEE ALSO"
pfilt(1), ra_bmp(1), ra_bn(1), ra_ppm(1), ra_pr(1), ra_pr24(1), ra_t8(1),
ra_t16(1), ximage(1)
Revision:	1.7
Committed:	Fri Oct 4 18:49:06 2024 UTC (8 months, 1 week ago) by greg
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.6:	+5 -1 lines
Log Message:	feat(ra_tiff): Added conversion of hyperspectral Radiance pictures on input
#	User	Rev	Content
1	greg	1.1	.\" SCCSid "@(#)ra_tiff.1 2.3 8/29/97 LBL"
2			.TH RA_TIFF 1 8/29/97 RADIANCE
3			.SH NAME
4			ra_tiff - convert RADIANCE picture to/from a TIFF color or greyscale image
5			.SH SYNOPSIS
6			.B ra_tiff
7			[
8	greg	1.2	.B "-z\|-L\|-l\|-f\|-w"
9	greg	1.1	][
10			.B -b
11			][
12			.B "-e +/-stops"
13			][
14			.B "-g gamma"
15			]
16			{
17	greg	1.6	.B "in.hdr\|-"
18	greg	1.1	}
19			.B out.tif
20			.br
21			.B "ra_tiff -r"
22			[
23			.B \-x
24			][
25			.B "\-g gamma"
26			][
27			.B "\-e +/-stops"
28			]
29			.B in.tif
30			[
31	greg	1.6	.B "out.hdr\|-"
32	greg	1.1	]
33			.SH DESCRIPTION
34			.I Ra_tiff
35			converts between RADIANCE and TIFF image formats.
36			The
37			.I \-g
38			option specifies the exponent used in gamma correction;
39			the default value is 2.2, which is the recommended value
40			for TIFF images.
41			.PP
42			The
43			.I \-b
44			option can be used to specify an 8-bit greyscale TIFF output file.
45			The type of input file is determined automatically.
46			.PP
47			The
48			.I \-z
49			option will result in LZW compression of the TIFF output file.
50			The
51			.I \-L
52			option specifies SGILOG compression, which is recommended
53			to capture the full dynamic range of the Radiance picture.
54			However, since many TIFF readers do not yet support this format,
55			use this option under advisement.
56			The
57			.I \-l
58	greg	1.2	option specifies SGILOG24 compressed output, which has
59	greg	1.1	less dynamic range than SGILOG, but may be smaller in some cases.
60	greg	1.2	(It is usually larger.)\0
61			The
62			.I \-f
63			option specifies 32-bit IEEE floating-point/primary output, which
64			is the highest resolution format but results in very large files, since
65	greg	1.3	each RGB pixel takes 96 bits (12 bytes) and does not compress well.
66	greg	1.2	The
67			.I \-w
68			option specifies 16-bit/primary output, which is understood by
69			some photo editing software, such as Adobe Photoshop.
70	greg	1.1	Decompression is automatically determined for TIFF input.
71			.PP
72			The
73			.I \-e
74			option specifies an exposure compensation in f-stops (powers of two).
75			Only integer stops are allowed, for efficiency.
76			.PP
77	greg	1.7	If the Radiance input is a hyperspectral picture, it will be
78			converted accurately if the output is anything but 24-bit RGB.
79			In the latter case, the converted colors will be approximate.
80			.PP
81	greg	1.1	The
82			.I \-r
83			option invokes a reverse conversion, from a TIFF image to
84			a RADIANCE picture.
85			The RADIANCE picture file can be taken from the standard input
86			or sent to the standard output by using a hyphen ('-') in place
87			of the file name, but the TIFF image must be to or from a file.
88			The
89			.I \-x
90			option can be used to specify an XYZE Radiance output file, rather
91			than the default RGBE.
92			.SH EXAMPLES
93			To convert a Radiance picture to SGILOG-compressed TIFF format:
94			.IP "" .2i
95	greg	1.6	ra_tiff \-L scene1.hdr scene1.tif
96	greg	1.1	.PP
97			To later convert this image back into Radiance and display using
98			human visibility tone-mapping:
99			.IP "" .2i
100	greg	1.6	ra_tiff \-r scene1.tif scene1.hdr
101	greg	1.1	.br
102	greg	1.6	ximage \-e human scene1.hdr
103	greg	1.1	.SH AUTHOR
104	greg	1.7	Greg Ward
105	greg	1.1	.br
106			Sam Leffler
107			.SH ACKNOWLEDGEMENT
108			Work on this program was initiated and sponsored by the LESO
109			group at EPFL in Switzerland.
110			Additions for the SGILOG data encoding were sponsored by Silicon Graphics, Inc.
111			.SH BUGS
112			Many TIFF file subtypes are not supported.
113			.br
114			A gamma value other than 2.2 is not properly recorded or understood if
115			recorded in the TIFF file.
116			.SH "SEE ALSO"
117	greg	1.4	pfilt(1), ra_bmp(1), ra_bn(1), ra_ppm(1), ra_pr(1), ra_pr24(1), ra_t8(1),
118	greg	1.1	ra_t16(1), ximage(1)