1pfstmo_mantiuk08(1) General Commands Manual pfstmo_mantiuk08(1)
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6 pfstmo_mantiuk08 - Display adaptive tone mapping
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9 pfstmo_mantiuk08 [--display-function <df-spec>] [--display-size=<size-
10 spec>] [--color-saturation <float>] [--contrast-enhancement <float>]
11 [--white-y=<float>] [--temporal=<pass>] [--output-tone-curve=<file
12 name>] [--verbose] [--help]
13
15 This command applies the display adaptive tone mapping, which attempts
16 to preserve contrast of an input (HDR) image as close as possible given
17 the characteristic of an output display. Use this tone mapping operator
18 if you want to preserve original image appearance, or slightly enhance
19 contrast (-e option) while maintaining the natural look of images. The
20 operator can also compensate for ambient light reflections on a screen,
21 and for varying dynamic range and brightness of a display.
22 More details can be found in:
24 Rafal Mantiuk, Scott Daly and Louis Kerofsky.
25 Display Adaptive Tone Mapping.
26 In: ACM Transactions on Graphics 27 (3), 2008.
27 http://www.mpi-inf.mpg.de/resources/hdr/datmo/
28 If you find this TMO useful in your research project, please cite the
30 paper above.
31 This operator also employs color correction mechanism from:
33 Radoslaw Mantiuk, Rafal Mantiuk, Anna Tomaszewska, Wolfgang Hei‐
34 drich.
35 Color Correction for Tone Mapping.
36 In: Computer Graphics Forum (Proc. of EUROGRAPHICS'09), 28(2),
37 2009.
38 http://zgk.wi.ps.pl/color_correction/
39 The result of this TMO does not require gamma correction.
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43 --display-function <df-spec>, -d <df-spec>
44 To adapt tone-mapping to different displays, this operator must
45 be provided a display function. The display function describes
46 how output luminance of a display changes with pixel values. If
47 no parameter is given, the command assumes -df pd=lcd (see Pre-
48 defined display below). There are several ways to specify the
49 display function:
50 Gamma-gain-black-ambient display model
52 g=<float>:l=<float>:b=<float>:k=<float>:a=<float>[:n=<float>]
54 Gamma-gain-black-ambient model can approximate a range of dis‐
56 plays and is a compact way to specify a display function. It
57 assumes that a display function has the following form:
58 L_d(I) = (l-b)*I^gamma + b + k/pi*a
60 The parameters are as follows:
62 g - gamma or exponent of a display function (default 2.2, usu‐
63 ally from 1.8 to 2.8)
64 l - peak luminance of a display in cd/m^2 (default 100, from
65 80 for CRTs to 500 or more for newer displays)
66 b - black level, which is luminance of a black pixel when the
67 display is on (default 1, usually from 0.3 to 1 cd/m^2)
68 k - reflectivity of a screen (assuming that it is diffuse)
69 (default 0.01, usually about 0.01 (1%) for LCD displays,
70 more for CRTs)
71 a - ambient illumination in lux. Typical values are:
72 50 lux Family living room (dim, default)
73 400 lux
74 A brightly lit office
75 32000 lux
76 Sunlight on an average day (min.)
77 100000 lux
78 Sunlight on an average day (max.)
79 Pre-defined display
81 pd=<display_type>
83 Use pre-defined display type. This options are for convenience
85 only and they do not mean to accurately model the response of a
86 particular display. The following display types are recognized:
87 lcd_office (g=2.2, l=100, b=0.8, k=0.01, a=400 )
89 lcd set to "office" mode seen in bright environment
90 lcd (g=2.2, l=200, b=0.8, k=0.01, a=60 )
91 typical lcd seen in dim environment (default)
92 lcd_bright (g=2.6, l=500, b=0.5, k=0.01, a=10 )
93 newer LCD TV seen in dark environment
94 crt (g=2.2, l=80, b=1, k=0.02, a=60 )
95 CRT monitor seen in dim environment
96 The parameters in the parenthesis are the same as for the gamma-
98 gain-black-ambient model explained above.
99 Lookup-table
101 lut=<file>
103 This is the most accurate specification of the display response
105 function, but requires measuring it with a luminance meter. The
106 lookup table should account also for ambient light, so that it
107 is recommended to use the luminance meter that can measure
108 screen luminance from a distance, such as Minolta LS-100 (as
109 opposed to those that use rubber tube touching a display that
110 eliminates the influence of ambient light). The <file> must be a
111 comma-separated text file in a format (CSV) with two columns:
112 first column represents pixel values (from 0.0 to 1.0) and the
113 second physical luminance in cd/m^2. Both the pixel value and
114 the luminance should increase in each raw.
115 --display-size=<size-spec>, -s=<size_spec>
117 Specifies how large the image appears to a viewer and what is
118 the viewing distance. If no parameter is given, -s ppd=30 is
119 assumed. Since this tone-mapper is global, display size has mod‐
120 erate effect on the resulting images and thus skipping this
121 parameter should not do much harm. There are two ways to specify
122 image size:
123 vres=<lines>:vd=<screen_heights>[:d=<meters>]
124 vres - screen's vertical resolution in lines, for exam‐
125 ple 1024.
126 vd - viewing distance specified as multiplies of
127 screen height. For example if the display is seen
128 from 0.5m and the height of its screen is 25cm,
129 vd=2.
130 d - (optional) viewing distance in meters. This is
131 to account for lower eye's sensitivity for larger
132 viewing distances (although the effect is negligi‐
133 ble). By default -d=0.5 is assumed.
134 ppd=<pixels_per_visual_degree>[:d=<meters>]
135 ppd - how many pixels spans one visual degree.
136 d - (optional) viewing distance in meters. This is
137 to account for lower eye's sensitivity for larger
138 viewing distances (although the effect is negligi‐
139 ble). By default -d=0.5 is assumed.
140 --color-saturation <float>, -c <float>
142 Decrease or increase color saturation after tone mapping.
143 Default value -c=1 attempts to preserve color appearance of the
144 original image. Use values >1 to increase and <1 to decrease
145 color saturation.
146 --contrast-enhancement <float>, -e <float>
148 By default this tone-mapper attempts to preserve contrast of an
149 input image (-e=1). This parameter controls whether the contrast
150 of an input image should be enhanced before tone-mapping. For
151 example -e=1.15 boosts contrast by 15%. Note that if a target
152 display does not offer sufficient dynamic range, contrast may be
153 enhanced only for selected tone-values (those that dominate in
154 an image) or not enhanced at all.
155 --white-y=<float>, -y=<float>
157 Tells the tone-mapper what luminance level in the input image
158 should be mapped to the maximum luminance of a display. Since
159 HDR images contain only relative luminance information, tone-
160 mapper does not know how bright should be the scene. This option
161 is meant to fix this problem by providing tone-mapper with the
162 information what luminance level in an input image should be
163 perceived as a diffuse white surface. Default is none, which
164 means that no such mapping will be enforced and tone-mapper is
165 free to find an optimal brightness for a given image. This is a
166 recommended setting for HDR images. Setting --white-y could be
167 necessary for dark scenes, which could be made too bright by the
168 tone-mapper. The value of this parameter can be also passed in
169 pfsstream as a tag WHITE_Y. pfstools 1.7 and newer sets set this
170 tag automatically for LDR images. The command line option over‐
171 rides the value of the pfstream tag.
172 --temporal=<pass>, -t=<pass>
174 Use temporal filtering of the tone-curve to tone-map video
175 sequence. This option should be used for video sequences to
176 avoid flickering. Since the temporal filter requires knowledge
177 of at least 25 frames in advance, the filtering must be per‐
178 formed in two passes, similar to MPEG video encoding. In the
179 first pass (pass=1) tone-curves are calculated for each frame
180 and stored in a temporary file (datmo_tone_curves.tmp in the
181 current directory). In the second pass (pass=2) the tone-curves
182 are read from that file, filtered and used to tone-map video
183 sequence. The tone-mapper does not produce any output (frames)
184 in the first pass. See below an example how to use two-pass fil‐
185 tering. Note that the same set of tone mapping options must be
186 provided for both passes.
187 --output-tone-curve=<file name>, -o=<file name>
189 Write tone-curves to a text file. This option is mainly for
190 debugging purposes, but can be used to visualize computed tone-
191 curves. The tone-curve data is stored in a comma separated text
192 file (CSV), consisting of three columns: frame number, log10 of
193 input luminance factor, log10 of the resulting display lumi‐
194 nance, and the pixel value (0-1).
195 --verbose, -v
197 Print additional information during program execution.
198 --quiet, -q
200 Do not display progress report.
201 --help, -h
203 Print list of commandline options.
204
206 pfsin memorial.hdr | pfstmo_mantiuk08 -d pd=crt | pfsout memorial.png
207 Tone map memorial image for a CRT display and store the result
209 in the PNG format.
210 pfsin memorial.hdr | pfstmo_mantiuk08 -d g=2.6:l=500:b=0.5:k=0.01:a=10
212 | pfsview
213 Tone map memorial image for a display that has a 2.2 gamma, the
215 peak luminance of 500 cd/m^2, the black level of 0.5 cd/m^2, the
216 panel reflectivity of 1% (0.01) and is seen under the illumina‐
217 tion of 10 lux.
218 pfsin bridge.jpg --linear | pfsclamp --min 0.007 | pfstmo_mantiuk08 -v
220 | pfsview
221 Enhance the low-dynamic range image 'bridge' and view the
223 result. pfsclamp command reduces noise for low code values.
224 pfsin frame%05d.exr | pfstmo_mantiuk08 -d pd=lcd_bright -t 1
226 pfsin frame%05d.exr | pfstmo_mantiuk08 -d pd=lcd_bright -t 2 | pfsout
227 out_frame%04d.png
228 Tone-map video sequence using 2-pass temporal filtering to avoid
230 flicker.
231 pfsin *.exr | pfstmo_mantiuk08 | pfsview
233 Tone-map and display *.exr HDR images in the current directory.
235 pfsin *.exr | pfstmo_mantiuk06 | pfsgamma -g 0.8 | pfstmo_mantiuk08 |
237 pfsview
238 It is possible to stack a TMO that sharpens images (pfstmo_man‐
240 tiuk06) with the contrast preserving TMO (pfstmo_mantiuk08) to
241 get new interesting results.
242
244 pfsin(1) pfsout(1) pfsview(1)
245
247 Please report bugs and comments to the pfstools discussion group
248 (http://groups.google.com/group/pfstools).
249 pfstmo_mantiuk08(1)