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 (7 months ago) by greg
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.7:	+6 -4 lines
Log Message:	feat(normtiff): Added ability to ingest hyperspectral radiance pictures
#	User	Rev	Content
1	greg	1.8	.\" RCSid $Id: normtiff.1,v 1.7 2021/04/07 21:13:52 greg Exp $
2	greg	1.1	.TH NORMTIFF 1 2/25/99 RADIANCE
3			.SH NAME
4	greg	1.2	normtiff - tone-map and convert RADIANCE picture or HDR TIFF to standard TIFF
5	greg	1.1	.SH SYNOPSIS
6			.B normtiff
7			[
8			.B options
9			]
10			.B input
11			.B output.tif
12			.SH DESCRIPTION
13			.I Normtiff
14	greg	1.2	prepares a Radiance picture or high dynamic-range TIFF
15	greg	1.1	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	greg	1.2	If the input is neither a RADIANCE picture nor a high dynamic-range TIFF,
38	greg	1.1	the program reports an error and exits.
39	greg	1.8	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	greg	1.1	.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	greg	1.2	If the input is a grayscale TIFF, this switch is
52	greg	1.1	automatically selected.
53			Otherwise, the output defaults to 24-bit RGB.
54			.TP
55	greg	1.3	.BR -z
56			Output LZW-compressed TIFF (smaller file).
57			.TP
58	greg	1.1	.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	greg	1.7	The default value is 100, which is typical for LCD monitors.
100	greg	1.1	.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	greg	1.5	normtiff \-b scene.hdr sceneb.tif
114	greg	1.1	.PP
115	greg	1.2	To condition a high dynamic-range TIFF for a particular film recorder with
116	greg	1.1	known color primaries, dynamic range and gamma response:
117			.IP "" .2i
118	greg	1.4	pcond \-d 50 \-g 2.5 \-p .580 .340 .281 .570 .153 .079 .333 .333 orig.tif filmrgb.tif
119	greg	1.1	.PP
120			To simulate human visual response on a monitor with known maximum luminance:
121			.IP "" .2i
122	greg	1.5	normtiff \-h \-u 80 scene.hdr sceneh.tif
123	greg	1.1	.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	1.8	Greg Ward
133	greg	1.1	.SH "SEE ALSO"
134			getinfo(1), pcond(1), pflip(1),
135			pvalue(1), protate(1), ra_xyze(1), rpict(1), ximage(1)