man/man1/falsecolor.1

.\" RCSid "$Id: falsecolor.1,v 1.11 2013/04/04 15:13:42 greg Exp $"
.TH "FALSECOLOR" "1" "12/12/11" "RADIANCE" ""
.SH "NAME"
falsecolor \- make a false color RADIANCE picture
.SH "SYNOPSIS"
.B falsecolor
[
.B "\-i input"
][
.B "\-p picture"
][
.B "\-cb | \-cl | \-cp"
][
.B \-e
][
.B "\-s scale"
][
.B "\-l label"
][
.B "\-n ndivs"
][
.B "\-lw lwidth"
][
.B "\-lh lheight"
][
.B "\-log decades"
][
.B "\-m mult"
][
.B "\-pal palette"
][
.B "\-r redv"
][
.B "\-g grnv"
][
.B "\-b bluv"
]

.B falsecolor \-palettes
.SH "DESCRIPTION"
.I Falsecolor
produces a false color picture for lighting analysis.
Input is a rendered Radiance picture.
.PP 
By default, luminance is displayed on a linear scale from 0 to 1000 cd/m2, where
dark areas are purple and brighter areas move through blue, green, red to yellow.
A different scale can be given with the
.I \-s
option.
If the argument given to
.I \-s
begins with an "a" for "auto," then the maximum is used for scaling the result.
The default multiplier is 179, which converts from radiance or irradiance
to luminance or illuminance, respectively.
A different multiplier can be given with
.I \-m
to get daylight factors or whatever.
For a logarithmic rather than a linear mapping, the
.I \-log
option can be used, where
.I decades
is the number of decades below the maximum scale desired.
.PP 
A legend is produced for the new image with a label given by the
.I \-l
option.
The default label is "cd/m2", which is appropriate for standard Radiance
images.
If the
.I \-i
option of
.I rpict(1)
was used to produce the image, then the appropriate label would be "Lux".
.PP 
If contour lines are desired rather than just false color, the
.I \-cl
option can be used.
These lines can be placed over another Radiance picture using the
.I \-p
option.
If the input picture is given with
.I \-ip
instead of
.I \-i,
then it will be used both as the source of values and as the picture
to overlay with contours.
The
.I \-cb
option produces contour bands instead of lines, where the thickness of
the bands is related to the rate of change in the image.
The
.I \-cp
option creates a posterization effect where colours are banded without
the background image showing through.
The
.I \-n
option can be used to change the number of contours (and corresponding
legend entries) from the default value of 8.
To ensure even divisions on a linear scale, set this value in consort with
.I \-s
such that the maximum is evenly divisible by twice the
.I \-n
setting minus one.
The
.I \-lw
and
.I \-lh
options may be used to change the legend dimensions from the default width
and height of 100x200.
A value of zero in either eliminates the legend in the output.
.PP 
The
.I \-e
option causes extrema points to be printed on the brightest and
darkest pixels of the input picture.
.PP 
The
.I "\-pal"
option provides different color palettes for
.I falsecolor.
The current choices are
.I spec
for the old spectral mapping,
.I hot
for a thermal scale,
.I eco
for a blue-red-yellow scale, and
.I pm3d
for a variation of the default mapping,
.I def.
A Radiance HDR image of all available palettes can be created with the 
.I \-palettes
option.
The remaining options,
.I "\-r, \-g,"
and
.I \-b
are for changing the mapping of values to colors.
These are expressions of the variable 
.I v,
where
.I v
varies from 0 to 1.
These options are not recommended for the casual user.
.PP 
If no
.I \-i
or
.I \-ip
option is used, input is taken from the standard input.
The output image is always written to standard output, which should
be redirected.
.SH "EXAMPLES"
To create a false color image directly from
.I rpict(1):
.IP "" .2i
rpict \-vf default.vp scene.oct | falsecolor > scene.hdr
.PP
To show the available color palettes:
.IP "" .2i
falsecolor -palettes | ximage
.PP 
To create a logarithmic contour plot of illuminance values on a
Radiance image:
.IP "" .2i
rpict \-i \-vf default.vp scene.oct > irrad.hdr
.br 
rpict \-vf default.vp scene.oct > rad.hdr
.br 
falsecolor \-i irrad.hdr \-p rad.hdr \-cl \-log 2 \-l Lux > lux.hdr
.SH "AUTHOR"
Greg Ward
.br 
Axel Jacobs (Perl translation and \-pal options)
.SH "ACKNOWLEDGEMENT"
Work on this program was initiated and sponsored by the LESO
group at EPFL in Switzerland. The 'eco' palette was sponsored by Foster + Partners in London.
.SH "SEE ALSO"
getinfo(1), pcomb(1), pcompos(1), pextrem(1), pfilt(1), pflip(1), protate(1),
psign(1), rpict(1), ximage(1)
Revision:	1.12
Committed:	Thu Sep 7 22:13:55 2017 UTC (7 years, 9 months ago) by greg
Branch:	MAIN
Changes since 1.11:	+6 -1 lines
Log Message:	Added comment about how to get even divisions
#	User	Rev	Content
1	greg	1.12	.\" RCSid "$Id: falsecolor.1,v 1.11 2013/04/04 15:13:42 greg Exp $"
2	greg	1.9	.TH "FALSECOLOR" "1" "12/12/11" "RADIANCE" ""
3			.SH "NAME"
4			falsecolor \- make a false color RADIANCE picture
5			.SH "SYNOPSIS"
6	greg	1.1	.B falsecolor
7			[
8			.B "\-i input"
9			][
10			.B "\-p picture"
11			][
12	greg	1.9	.B "\-cb \| \-cl \| \-cp"
13	greg	1.1	][
14			.B \-e
15			][
16			.B "\-s scale"
17			][
18			.B "\-l label"
19			][
20			.B "\-n ndivs"
21			][
22	greg	1.3	.B "\-lw lwidth"
23			][
24			.B "\-lh lheight"
25			][
26	greg	1.1	.B "\-log decades"
27			][
28			.B "\-m mult"
29			][
30	greg	1.7	.B "\-pal palette"
31	greg	1.4	][
32	greg	1.1	.B "\-r redv"
33			][
34			.B "\-g grnv"
35			][
36			.B "\-b bluv"
37			]
38	greg	1.9
39			.B falsecolor \-palettes
40			.SH "DESCRIPTION"
41	greg	1.1	.I Falsecolor
42			produces a false color picture for lighting analysis.
43			Input is a rendered Radiance picture.
44	greg	1.9	.PP
45			By default, luminance is displayed on a linear scale from 0 to 1000 cd/m2, where
46			dark areas are purple and brighter areas move through blue, green, red to yellow.
47	greg	1.1	A different scale can be given with the
48			.I \-s
49			option.
50	greg	1.4	If the argument given to
51			.I \-s
52			begins with an "a" for "auto," then the maximum is used for scaling the result.
53	greg	1.1	The default multiplier is 179, which converts from radiance or irradiance
54			to luminance or illuminance, respectively.
55			A different multiplier can be given with
56			.I \-m
57			to get daylight factors or whatever.
58			For a logarithmic rather than a linear mapping, the
59			.I \-log
60			option can be used, where
61			.I decades
62			is the number of decades below the maximum scale desired.
63	greg	1.9	.PP
64	greg	1.1	A legend is produced for the new image with a label given by the
65			.I \-l
66			option.
67	greg	1.9	The default label is "cd/m2", which is appropriate for standard Radiance
68	greg	1.1	images.
69			If the
70	greg	1.9	.I \-i
71	greg	1.1	option of
72			.I rpict(1)
73			was used to produce the image, then the appropriate label would be "Lux".
74	greg	1.9	.PP
75	greg	1.1	If contour lines are desired rather than just false color, the
76			.I \-cl
77			option can be used.
78			These lines can be placed over another Radiance picture using the
79	greg	1.9	.I \-p
80	greg	1.1	option.
81			If the input picture is given with
82			.I \-ip
83			instead of
84			.I \-i,
85			then it will be used both as the source of values and as the picture
86			to overlay with contours.
87			The
88			.I \-cb
89			option produces contour bands instead of lines, where the thickness of
90			the bands is related to the rate of change in the image.
91			The
92	greg	1.9	.I \-cp
93			option creates a posterization effect where colours are banded without
94			the background image showing through.
95			The
96	greg	1.1	.I \-n
97			option can be used to change the number of contours (and corresponding
98			legend entries) from the default value of 8.
99	greg	1.12	To ensure even divisions on a linear scale, set this value in consort with
100			.I \-s
101			such that the maximum is evenly divisible by twice the
102			.I \-n
103			setting minus one.
104	greg	1.3	The
105			.I \-lw
106			and
107			.I \-lh
108			options may be used to change the legend dimensions from the default width
109			and height of 100x200.
110			A value of zero in either eliminates the legend in the output.
111	greg	1.9	.PP
112	greg	1.1	The
113			.I \-e
114			option causes extrema points to be printed on the brightest and
115			darkest pixels of the input picture.
116	greg	1.9	.PP
117	greg	1.4	The
118	greg	1.7	.I "\-pal"
119			option provides different color palettes for
120	greg	1.4	.I falsecolor.
121	greg	1.7	The current choices are
122			.I spec
123			for the old spectral mapping,
124			.I hot
125	greg	1.10	for a thermal scale,
126			.I eco
127	greg	1.11	for a blue-red-yellow scale, and
128	greg	1.7	.I pm3d
129			for a variation of the default mapping,
130			.I def.
131	greg	1.9	A Radiance HDR image of all available palettes can be created with the
132			.I \-palettes
133			option.
134	greg	1.1	The remaining options,
135			.I "\-r, \-g,"
136			and
137			.I \-b
138			are for changing the mapping of values to colors.
139			These are expressions of the variable
140			.I v,
141			where
142			.I v
143			varies from 0 to 1.
144			These options are not recommended for the casual user.
145	greg	1.9	.PP
146	greg	1.1	If no
147			.I \-i
148			or
149			.I \-ip
150			option is used, input is taken from the standard input.
151			The output image is always written to standard output, which should
152			be redirected.
153	greg	1.9	.SH "EXAMPLES"
154	greg	1.1	To create a false color image directly from
155			.I rpict(1):
156			.IP "" .2i
157	greg	1.6	rpict \-vf default.vp scene.oct \| falsecolor > scene.hdr
158	greg	1.10	.PP
159			To show the available color palettes:
160			.IP "" .2i
161			falsecolor -palettes \| ximage
162	greg	1.9	.PP
163	greg	1.1	To create a logarithmic contour plot of illuminance values on a
164			Radiance image:
165			.IP "" .2i
166	greg	1.6	rpict \-i \-vf default.vp scene.oct > irrad.hdr
167	greg	1.9	.br
168	greg	1.6	rpict \-vf default.vp scene.oct > rad.hdr
169	greg	1.9	.br
170	greg	1.6	falsecolor \-i irrad.hdr \-p rad.hdr \-cl \-log 2 \-l Lux > lux.hdr
171	greg	1.9	.SH "AUTHOR"
172	greg	1.1	Greg Ward
173	greg	1.9	.br
174			Axel Jacobs (Perl translation and \-pal options)
175			.SH "ACKNOWLEDGEMENT"
176	greg	1.1	Work on this program was initiated and sponsored by the LESO
177	greg	1.10	group at EPFL in Switzerland. The 'eco' palette was sponsored by Foster + Partners in London.
178	greg	1.1	.SH "SEE ALSO"
179			getinfo(1), pcomb(1), pcompos(1), pextrem(1), pfilt(1), pflip(1), protate(1),
180			psign(1), rpict(1), ximage(1)