man/man1/ximage.1

.\" RCSid "$Id: ximage.1,v 1.6 2010/01/07 17:52:38 greg Exp $"
.TH XIMAGE 1 10/27/98 RADIANCE
.SH NAME
ximage - RADIANCE picture display for X window system
.SH SYNOPSIS
.B ximage
[
.B \=geometry
][
.B "\-di display"
][
.B "\-c ncolors"
][
.B \-d
][
.B \-b
][
.B \-m
][
.B "\-g gamma"
][
.B \-f
][
.B "\-e spec
][
.BI -o spec
][
.B "\-t intvl"
][
.B \-s
]
.B "picture .."
.SH DESCRIPTION
.I Ximage
takes one or more RADIANCE picture files
and displays them on an X server.
The
.I \-c
option specifies the number of colors to use (default fills color table).
The
.I \-d
option turns off color dithering.
The
.I \-b
option displays the image in black and white (greyscale).
The
.I \-m
option forces monochrome output.
The
.I \-g
option specifies the exponent used in gamma correction;
the default value is 2.2.
The
.I \-f
option stores a Pixmap on the server side for faster refresh.
This may not work with large images on some servers.
The
.I \-o
option specifies a sequence of information to print to the standard
output for the 't' command (see below).
The
.I \-t
option specifies a minimum interval (in milliseconds)
between successive ray outputs
in mouse tracking mode (right button pressed).
.PP
The
.I \-e
option specifies an exposure compensation in f-stops (powers of two).
Only integer stops are allowed, for efficiency.
If the special word,
.I auto
is given instead of a number of stops, then
.I ximage
performs an automatic exposure adjustment similar to
.I pcond(1),
compressing the dynamic range of the image to fit
within the dynamic range of the display.
If the special word,
.I human
is given instead, then
.I ximage
performs an exposure adjustment similar to
.I pcond
with the
.I \-s
and
.I \-c
options, which compensate for human contrast and color sensitivity
at the corresponding scene luminance levels.
This option yeilds and appearance of the scene on the display that
closely matches what would be experienced in the real world.
.PP
The
.I \-s
option tells
.I ximage
to display multiple pictures sequentially, rather than all at once.
If no
.I picture
is given, input is read from stdin provided either the
.I \-b
or
.I \-m
option is in effect, or the X server is capable of 24-bit color.
However, many of the commands given below will not work.
.SH COMMANDS
Once a picture is displayed, the user
may perform a number of operations.
Some of the operations make use of an area of interest, defined by pressing
the left mouse button and dragging the cursor over a section of the image.
Pressing the button and immediately releasing it defines a single point as
the area of interest.
A command is a single character.
.TP 10n
.BR q
Quit picture.
(Also Q or ^D.)\0
.TP 10
.BR <space>
Redraw the area of interest.
.TP 10
.BR ^R
Redraw the entire image.
.TP
.BR <return>
Display the radiance averaged over the area of interest.
The maximum of the three (RGB) channels is reported.
.TP
.BR l
Display the photometrically-weighted luminance value in the area of interest.
This assumes that the image was correctly computed in terms of
luminance.
.TP
.BR c
Display the color in the area of interest, as adjusted by the current
exposure setting.
.TP
.BR p
Display the x and y location of the cursor.
.TP
.BR i
Identify identical pixels by assigning a random color at the cursor position.
This is useful for displaying contours, especially when combined
with the \-b option.
.TP
.BR t
Print information about the pixel under the cursor
according to the string following the
.I \-o
command line option.
The valid characters for this option correspond roughly to the other
.I ximage
commands:
.IP
o       ray origin
.IP
d       ray direction
.IP
v       radiance value
.IP
l       luminance value
.IP
p       pixel position
.IP
The default output is "\-ood", which prints
the ray origin and direction.
This can be used as input to rtrace(1) to get additional information
about the image (ie. pipe the output of ximage into rtrace).
Pressing the middle mouse button is equivalent to typing the 't' key.
Pressing and holding the right mouse button is equivalent to
continuously pressing the 't' key.
.TP
.BR =
Adjust the exposure to the area of interest.
A crude adjustment is made immediately, and the number of stops
is printed while the colors are resampled.
After a few seconds to a minute, the final image is redisplayed.
If the area of interest is already within 1/2 stop of the ideal,
no adjustment is made.
.TP
.BR @
Same as '=' command, only the exposure is adjusted to provide
roughly the same visibility for the selected region
on screen as a viewer would experience
in the actual space.
Like the 'l' command, this adjustment assumes that the image
has been correctly computed in terms of luminance.
(See also the 'h' command, below.)
.TP
.BR a
Perform automatic exposure compensation, as if
.I ximage
were started with the
.I "\-e auto"
option.
If a rectangular area has been selected, the pixels in this region
will be emphasized in the histogram, offering this area exposure preference.
(Each pixel within the rectangle will be weighted as 21 outside pixels.)
.TP
.BR h
Perform human expsoure compensation, as if
.I ximage
were started with the
.I "\-e human"
option.
See the 'a' command above regarding pixel weighting.
.TP
.BR 0
Reset the origin to the upper left corner of the image.
This command is used to restore the original image position after
using the shift or control key with the mouse to relocate the image
within the frame (see below).
.TP
.BR f
Switch on the fast redraw option
.I (\-f),
loading the image pixmap over to the server side.
This command is useful when network delays are causing slow image
refresh, and the user didn't notice it until after
.I ximage
was started.
.TP
.BR F
Switch off the fast redraw option.
This frees up some memory on the server, as well as the color table
for other windows.
.PP
In addition to the commands listed above, the control or shift key may
be held while the cursor is dragged to reposition the image within the
window.
.SH "X RESOURCES"
radiance.gamma  the default gamma correction value
.SH ENVIRONMENT
DISPLAY_GAMMA           the default gamma correction value
.SH AUTHORS
Greg Ward
.br
Anat Grynberg (Paris)
.br
Philip Thompson (MIT)
.SH "SEE ALSO"
aedimage(1), normtiff(1), pcond(1), pfilt(1), rpict(1), rtrace(1),
rvu(1), xglaresrc(1), xshowtrace(1)
Revision:	1.7
Committed:	Thu Jan 7 17:54:56 2010 UTC (15 years, 9 months ago) by greg
Branch:	MAIN
CVS Tags:	rad4R0
Changes since 1.6:	+2 -2 lines
Log Message:	Further clarification
#	User	Rev	Content
1	greg	1.7	.\" RCSid "$Id: ximage.1,v 1.6 2010/01/07 17:52:38 greg Exp $"
2	greg	1.1	.TH XIMAGE 1 10/27/98 RADIANCE
3			.SH NAME
4	greg	1.2	ximage - RADIANCE picture display for X window system
5	greg	1.1	.SH SYNOPSIS
6			.B ximage
7			[
8			.B \=geometry
9			][
10			.B "\-di display"
11			][
12			.B "\-c ncolors"
13			][
14			.B \-d
15			][
16			.B \-b
17			][
18			.B \-m
19			][
20			.B "\-g gamma"
21			][
22			.B \-f
23			][
24			.B "\-e spec
25			][
26			.BI -o spec
27			][
28			.B "\-t intvl"
29			][
30			.B \-s
31			]
32			.B "picture .."
33			.SH DESCRIPTION
34			.I Ximage
35			takes one or more RADIANCE picture files
36			and displays them on an X server.
37			The
38			.I \-c
39			option specifies the number of colors to use (default fills color table).
40			The
41			.I \-d
42			option turns off color dithering.
43			The
44			.I \-b
45			option displays the image in black and white (greyscale).
46			The
47			.I \-m
48			option forces monochrome output.
49			The
50			.I \-g
51			option specifies the exponent used in gamma correction;
52			the default value is 2.2.
53			The
54			.I \-f
55			option stores a Pixmap on the server side for faster refresh.
56			This may not work with large images on some servers.
57			The
58			.I \-o
59			option specifies a sequence of information to print to the standard
60			output for the 't' command (see below).
61			The
62			.I \-t
63			option specifies a minimum interval (in milliseconds)
64			between successive ray outputs
65			in mouse tracking mode (right button pressed).
66			.PP
67			The
68			.I \-e
69			option specifies an exposure compensation in f-stops (powers of two).
70			Only integer stops are allowed, for efficiency.
71			If the special word,
72			.I auto
73			is given instead of a number of stops, then
74			.I ximage
75			performs an automatic exposure adjustment similar to
76			.I pcond(1),
77			compressing the dynamic range of the image to fit
78			within the dynamic range of the display.
79			If the special word,
80			.I human
81			is given instead, then
82			.I ximage
83			performs an exposure adjustment similar to
84			.I pcond
85			with the
86			.I \-s
87			and
88			.I \-c
89			options, which compensate for human contrast and color sensitivity
90			at the corresponding scene luminance levels.
91			This option yeilds and appearance of the scene on the display that
92			closely matches what would be experienced in the real world.
93			.PP
94			The
95			.I \-s
96			option tells
97			.I ximage
98			to display multiple pictures sequentially, rather than all at once.
99			If no
100			.I picture
101			is given, input is read from stdin provided either the
102			.I \-b
103			or
104			.I \-m
105			option is in effect, or the X server is capable of 24-bit color.
106			However, many of the commands given below will not work.
107			.SH COMMANDS
108			Once a picture is displayed, the user
109			may perform a number of operations.
110			Some of the operations make use of an area of interest, defined by pressing
111			the left mouse button and dragging the cursor over a section of the image.
112			Pressing the button and immediately releasing it defines a single point as
113			the area of interest.
114			A command is a single character.
115			.TP 10n
116			.BR q
117			Quit picture.
118			(Also Q or ^D.)\0
119			.TP 10
120			.BR <space>
121			Redraw the area of interest.
122			.TP 10
123			.BR ^R
124			Redraw the entire image.
125			.TP
126			.BR <return>
127			Display the radiance averaged over the area of interest.
128	greg	1.6	The maximum of the three (RGB) channels is reported.
129	greg	1.1	.TP
130			.BR l
131	greg	1.7	Display the photometrically-weighted luminance value in the area of interest.
132	greg	1.1	This assumes that the image was correctly computed in terms of
133			luminance.
134			.TP
135			.BR c
136	greg	1.6	Display the color in the area of interest, as adjusted by the current
137			exposure setting.
138	greg	1.1	.TP
139			.BR p
140			Display the x and y location of the cursor.
141			.TP
142			.BR i
143			Identify identical pixels by assigning a random color at the cursor position.
144			This is useful for displaying contours, especially when combined
145	greg	1.5	with the \-b option.
146	greg	1.1	.TP
147			.BR t
148			Print information about the pixel under the cursor
149			according to the string following the
150			.I \-o
151			command line option.
152			The valid characters for this option correspond roughly to the other
153			.I ximage
154			commands:
155			.IP
156			o ray origin
157			.IP
158			d ray direction
159			.IP
160			v radiance value
161			.IP
162			l luminance value
163			.IP
164			p pixel position
165			.IP
166	greg	1.5	The default output is "\-ood", which prints
167	greg	1.1	the ray origin and direction.
168			This can be used as input to rtrace(1) to get additional information
169			about the image (ie. pipe the output of ximage into rtrace).
170			Pressing the middle mouse button is equivalent to typing the 't' key.
171			Pressing and holding the right mouse button is equivalent to
172			continuously pressing the 't' key.
173			.TP
174			.BR =
175			Adjust the exposure to the area of interest.
176			A crude adjustment is made immediately, and the number of stops
177			is printed while the colors are resampled.
178			After a few seconds to a minute, the final image is redisplayed.
179			If the area of interest is already within 1/2 stop of the ideal,
180			no adjustment is made.
181			.TP
182			.BR @
183			Same as '=' command, only the exposure is adjusted to provide
184			roughly the same visibility for the selected region
185			on screen as a viewer would experience
186			in the actual space.
187			Like the 'l' command, this adjustment assumes that the image
188			has been correctly computed in terms of luminance.
189			(See also the 'h' command, below.)
190			.TP
191			.BR a
192			Perform automatic exposure compensation, as if
193			.I ximage
194			were started with the
195			.I "\-e auto"
196			option.
197			If a rectangular area has been selected, the pixels in this region
198			will be emphasized in the histogram, offering this area exposure preference.
199			(Each pixel within the rectangle will be weighted as 21 outside pixels.)
200			.TP
201			.BR h
202			Perform human expsoure compensation, as if
203			.I ximage
204			were started with the
205			.I "\-e human"
206			option.
207			See the 'a' command above regarding pixel weighting.
208			.TP
209			.BR 0
210			Reset the origin to the upper left corner of the image.
211			This command is used to restore the original image position after
212			using the shift or control key with the mouse to relocate the image
213			within the frame (see below).
214			.TP
215			.BR f
216			Switch on the fast redraw option
217			.I (\-f),
218			loading the image pixmap over to the server side.
219			This command is useful when network delays are causing slow image
220			refresh, and the user didn't notice it until after
221			.I ximage
222			was started.
223			.TP
224			.BR F
225			Switch off the fast redraw option.
226			This frees up some memory on the server, as well as the color table
227			for other windows.
228			.PP
229			In addition to the commands listed above, the control or shift key may
230			be held while the cursor is dragged to reposition the image within the
231			window.
232			.SH "X RESOURCES"
233			radiance.gamma the default gamma correction value
234			.SH ENVIRONMENT
235			DISPLAY_GAMMA the default gamma correction value
236			.SH AUTHORS
237			Greg Ward
238			.br
239			Anat Grynberg (Paris)
240			.br
241			Philip Thompson (MIT)
242			.SH "SEE ALSO"
243			aedimage(1), normtiff(1), pcond(1), pfilt(1), rpict(1), rtrace(1),
244	greg	1.4	rvu(1), xglaresrc(1), xshowtrace(1)