man/man1/normtiff.1

.\" RCSid $Id: normtiff.1,v 1.7 2021/04/07 21:13:52 greg Exp $
.TH NORMTIFF 1 2/25/99 RADIANCE
.SH NAME
normtiff - tone-map and convert RADIANCE picture or HDR TIFF to standard TIFF
.SH SYNOPSIS
.B normtiff
[
.B options
]
.B input
.B output.tif
.SH DESCRIPTION
.I Normtiff
prepares a Radiance picture or high dynamic-range TIFF
for output to a display or hard copy device.
If the dynamic range of the scene exceeds that of the display (as is
usually the case),
.I normtiff
will compress the dynamic range of the picture such that both
dark and bright regions are visible.
In addition, certain limitations in human vision may be mimicked in
order to provide an appearance similar to the experience one might
have in the actual scene.
.PP
Output is always an uncompressed RGB TIFF, which must be named
on the command line along with the input file.
If the input file has a ".tif" or ".tiff" extension,
.I normtiff
attempts to read it as a TIFF.
Otherwise,
.I normtiff
first tries opening it as a RADIANCE picture, only opening it
as a TIFF if it fails header inspection.
(See the
.I getinfo(1)
program.)\0
If the input is neither a RADIANCE picture nor a high dynamic-range TIFF,
the program reports an error and exits.
Hyperspectral radiance pictures are silently converted to RGB, though
the colors will be more accurate if the HSR picture is passed through
.I ra_xyze(1),
first.
.PP
The following command line options are understood.
Since this program is very similar to
.I pcond(1),
several of the switches are identical.
.TP 10n
.BR -b
Toggle 8-bit black and white (grayscale) TIFF output.
If the input is a grayscale TIFF, this switch is
automatically selected.
Otherwise, the output defaults to 24-bit RGB.
.TP
.BR -z
Output LZW-compressed TIFF (smaller file).
.TP
.BR -h
Mimic human visual response in the output.
The goal of this process is to produce output that correlates
strongly with a person's subjective impression of a scene.
This switch turns on both the
.I \-s
and
.I \-c
switches, described below.
.TP
.BR -s
Toggle the use of the human contrast sensitivity function in determining the
exposure for the image.
A darker scene will have relatively lower exposure with lower
contrast than a well-lit scene.
.TP
.BR -c
Toggle mesopic color correction.
If parts of the image are in the mesopic or scotopic range where
the cone photoreceptors lose their efficiency, this switch will
cause a corresponding loss of color visibility in the output and a
shift to a scotopic (blue-dominant) response function.
.TP
.BR -l
Toggle the use of a linear response function versus the standard dynamic
range compression algorithm.
This may make some parts of the resulting image too
dark or too bright to see.
.TP
.BI -u \ Ldmax
Specifies the top of the luminance range for the target output device.
That is, the luminance (in candelas/m^2) for an output pixel value
of (R,G,B)=(255,255,255).
This parameter affects tone mapping only when the
.I \-s
switch is on.
The default value is 100 cd/m^2.
.TP
.BI -d \ Lddyn
Specifies the dynamic range for the target output device, which is
the ratio of the maximum and minimum usable display luminances.
The default value is 100, which is typical for LCD monitors.
.TP
.BI -p " xr yr xg yg xb yb xw yw"
Specifies the RGB primaries for the target output device.
These are the 1931 CIE (x,y) chromaticity values for red, green,
blue and white, respectively.
.TP
.BI -g \ gamma
Specifies the output device gamma correction value.
The default value is 2.2, which is appropriate for most CRT monitors.
(A value of 1.8 is common in color prepress and color printers.)\0
.SH EXAMPLES
To convert a RADIANCE picture to an 8-bit grayscale TIFF:
.IP "" .2i
normtiff \-b scene.hdr sceneb.tif
.PP
To condition a high dynamic-range TIFF for a particular film recorder with
known color primaries, dynamic range and gamma response:
.IP "" .2i
pcond \-d 50 \-g 2.5 \-p .580 .340 .281 .570 .153 .079 .333 .333 orig.tif filmrgb.tif
.PP
To simulate human visual response on a monitor with known maximum luminance:
.IP "" .2i
normtiff \-h \-u 80 scene.hdr sceneh.tif
.SH REFERENCE
Greg Ward Larson, Holly Rushmeier, Christine Piatko,
``A Visibility Matching Tone Reproduction Operator for High Dynamic Range
Scenes,''
.I "IEEE Transactions on Visualization and Computer Graphics",
December 1997.
.PP
http://positron.cs.berkeley.edu/gwlarson/pixformat/
.SH AUTHOR
Greg Ward
.SH "SEE ALSO"
getinfo(1), pcond(1), pflip(1), 
pvalue(1), protate(1), ra_xyze(1), rpict(1), ximage(1)
Revision:	1.8
Committed:	Wed Oct 2 15:58:56 2024 UTC (12 months, 3 weeks ago) by greg
Branch:	MAIN
CVS Tags:	rad6R0, HEAD
Changes since 1.7:	+6 -4 lines
Log Message:	feat(normtiff): Added ability to ingest hyperspectral radiance pictures
#	Content
1	.\" RCSid $Id: normtiff.1,v 1.7 2021/04/07 21:13:52 greg Exp $
2	.TH NORMTIFF 1 2/25/99 RADIANCE
3	.SH NAME
4	normtiff - tone-map and convert RADIANCE picture or HDR TIFF to standard TIFF
5	.SH SYNOPSIS
6	.B normtiff
7	[
8	.B options
9	]
10	.B input
11	.B output.tif
12	.SH DESCRIPTION
13	.I Normtiff
14	prepares a Radiance picture or high dynamic-range TIFF
15	for output to a display or hard copy device.
16	If the dynamic range of the scene exceeds that of the display (as is
17	usually the case),
18	.I normtiff
19	will compress the dynamic range of the picture such that both
20	dark and bright regions are visible.
21	In addition, certain limitations in human vision may be mimicked in
22	order to provide an appearance similar to the experience one might
23	have in the actual scene.
24	.PP
25	Output is always an uncompressed RGB TIFF, which must be named
26	on the command line along with the input file.
27	If the input file has a ".tif" or ".tiff" extension,
28	.I normtiff
29	attempts to read it as a TIFF.
30	Otherwise,
31	.I normtiff
32	first tries opening it as a RADIANCE picture, only opening it
33	as a TIFF if it fails header inspection.
34	(See the
35	.I getinfo(1)
36	program.)\0
37	If the input is neither a RADIANCE picture nor a high dynamic-range TIFF,
38	the program reports an error and exits.
39	Hyperspectral radiance pictures are silently converted to RGB, though
40	the colors will be more accurate if the HSR picture is passed through
41	.I ra_xyze(1),
42	first.
43	.PP
44	The following command line options are understood.
45	Since this program is very similar to
46	.I pcond(1),
47	several of the switches are identical.
48	.TP 10n
49	.BR -b
50	Toggle 8-bit black and white (grayscale) TIFF output.
51	If the input is a grayscale TIFF, this switch is
52	automatically selected.
53	Otherwise, the output defaults to 24-bit RGB.
54	.TP
55	.BR -z
56	Output LZW-compressed TIFF (smaller file).
57	.TP
58	.BR -h
59	Mimic human visual response in the output.
60	The goal of this process is to produce output that correlates
61	strongly with a person's subjective impression of a scene.
62	This switch turns on both the
63	.I \-s
64	and
65	.I \-c
66	switches, described below.
67	.TP
68	.BR -s
69	Toggle the use of the human contrast sensitivity function in determining the
70	exposure for the image.
71	A darker scene will have relatively lower exposure with lower
72	contrast than a well-lit scene.
73	.TP
74	.BR -c
75	Toggle mesopic color correction.
76	If parts of the image are in the mesopic or scotopic range where
77	the cone photoreceptors lose their efficiency, this switch will
78	cause a corresponding loss of color visibility in the output and a
79	shift to a scotopic (blue-dominant) response function.
80	.TP
81	.BR -l
82	Toggle the use of a linear response function versus the standard dynamic
83	range compression algorithm.
84	This may make some parts of the resulting image too
85	dark or too bright to see.
86	.TP
87	.BI -u \ Ldmax
88	Specifies the top of the luminance range for the target output device.
89	That is, the luminance (in candelas/m^2) for an output pixel value
90	of (R,G,B)=(255,255,255).
91	This parameter affects tone mapping only when the
92	.I \-s
93	switch is on.
94	The default value is 100 cd/m^2.
95	.TP
96	.BI -d \ Lddyn
97	Specifies the dynamic range for the target output device, which is
98	the ratio of the maximum and minimum usable display luminances.
99	The default value is 100, which is typical for LCD monitors.
100	.TP
101	.BI -p " xr yr xg yg xb yb xw yw"
102	Specifies the RGB primaries for the target output device.
103	These are the 1931 CIE (x,y) chromaticity values for red, green,
104	blue and white, respectively.
105	.TP
106	.BI -g \ gamma
107	Specifies the output device gamma correction value.
108	The default value is 2.2, which is appropriate for most CRT monitors.
109	(A value of 1.8 is common in color prepress and color printers.)\0
110	.SH EXAMPLES
111	To convert a RADIANCE picture to an 8-bit grayscale TIFF:
112	.IP "" .2i
113	normtiff \-b scene.hdr sceneb.tif
114	.PP
115	To condition a high dynamic-range TIFF for a particular film recorder with
116	known color primaries, dynamic range and gamma response:
117	.IP "" .2i
118	pcond \-d 50 \-g 2.5 \-p .580 .340 .281 .570 .153 .079 .333 .333 orig.tif filmrgb.tif
119	.PP
120	To simulate human visual response on a monitor with known maximum luminance:
121	.IP "" .2i
122	normtiff \-h \-u 80 scene.hdr sceneh.tif
123	.SH REFERENCE
124	Greg Ward Larson, Holly Rushmeier, Christine Piatko,
125	``A Visibility Matching Tone Reproduction Operator for High Dynamic Range
126	Scenes,''
127	.I "IEEE Transactions on Visualization and Computer Graphics",
128	December 1997.
129	.PP
130	http://positron.cs.berkeley.edu/gwlarson/pixformat/
131	.SH AUTHOR
132	Greg Ward
133	.SH "SEE ALSO"
134	getinfo(1), pcond(1), pflip(1),
135	pvalue(1), protate(1), ra_xyze(1), rpict(1), ximage(1)