Man page - pfsdisplayfunction(1)
Packages contains this manual
- jpeg2hdrgen(1)
- pfsoutrgbe(1)
- pfsouthdrhtml(1)
- pfsextractchannels(1)
- pfsinrgbe(1)
- pfsout(1)
- pfsstat(1)
- pfscolortransform(1)
- pfsoutyuv(1)
- pfsoutppm(1)
- dcraw2hdrgen(1)
- pfsinimgmagick(1)
- pfsclamp(1)
- pfsgamma(1)
- pfsin(1)
- pfsplotresponse(1)
- pfsoctavelum(1)
- pfsoutimgmagick(1)
- pfsinme(1)
- pfsretime(1)
- pfsoctavergb(1)
- pfsrotate(1)
- pfsinhdrgen(1)
- pfstag(1)
- pfscat(1)
- pfssize(1)
- pfsindcraw(1)
- pfsdisplayfunction(1)
- pfsabsolute(1)
- pfsouttiff(1)
- pfscut(1)
- pfsinexr(1)
- pfspanoramic(1)
- pfshdrcalibrate(1)
- pfsinppm(1)
- pfspad(1)
- pfsoutpfm(1)
- pfsintiff(1)
- pfsinpfm(1)
- pfsflip(1)
- pfs_automerge(1)
- pfsoutexr(1)
- pfsinyuv(1)
apt-get install pfstools
Manual
pfsdisplayfunction
NAMESYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
BUGS
NAME
pfsdisplayfunction - Apply display function to color or gray-scale images
SYNOPSIS
pfsdisplayfunction [ --display-function < df-spec >] [-- to-pixels | -- to-luminance ] [-- help ] [-- verbose ]
DESCRIPTION
Use this command to convert pixel values to luminance / radiance units displayed on a monitor or to perform inverse conversion. This command is useful in combination with the HDR-VDP to convert LDR images to luminance maps representing images shown on a particular display. The display function specification is identical to the specification used in the pfstmo_mantiuk08 tone mapping operator (from the pfstmo package).
If neither -- to-luminance nor -- to-pixels option is specified, the appropriate conversion direction will be deducted from the LUMINANCE tag in the pfs stream.
OPTIONS
-- to-luminance , - l
Convert pixel values to absolute luminance / radiance units. For RGB images the same display function is applied in each color channel.
-- to-pixels , - p
Convert absolute luminance / radiance units to pixel values. For RGB images the same display function is applied in each color channel.
--display-function < df-spec >, -d < df-spec >
The display function describes how output luminance of a display changes with pixel values. If no parameter is given, the command assumes -df pd=lcd (see Pre-defined display below). There are several ways to specify the display function:
Gamma-gain-black-ambient display model
g=<float>:l=<float>:b=<float>:k=<float>:a=<float>[:n=<float>]
Gamma-gain-black-ambient model can approximate a range of displays and is a compact way to specify a display function. It assumes that a display function has the following form:
L_d(I) = (l-b)*Iˆgamma + b + k/pi*a
The parameters are as follows:
|
g - |
gamma or exponent of a display function (default 2.2, usually from 1.8 to 2.8) |
||
|
l - |
peak luminance of a display in cd/mˆ2 (default 100, from 80 for CRTs to 500 or more for newer displays) |
||
|
b - |
black level, which is luminance of a black pixel when the display is on (default 1, usually from 0.3 to 1 cd/mˆ2) |
||
|
k - |
reflectivity of a screen (assuming that it is diffuse) (default 0.01, usually about 0.01 (1%) for LCD displays, more for CRTs) |
||
|
a - |
ambient illumination in lux. Typical values are: |
50 lux
|
Family living room (dim, default ) |
400 lux
A brightly lit office
32000 lux
Sunlight on an average day (min.)
100000 lux
Sunlight on an average day (max.)
Pre-defined display
pd = <display_type>
Use pre-defined
display type. This options are for convenience only and they
do not mean to accurately model the response of a particular
display. The following
display type
s are recognized:
lcd_office
(g=2.2, l=100, b=0.8, k=0.01, a=400 )
lcd set to "office" mode seen in bright environment
lcd (g=2.2, l=200, b=0.8, k=0.01, a=60 )
typical lcd seen in dim environment ( default )
lcd_bright (g=2.6, l=500, b=0.5, k=0.01, a=10 )
newer LCD TV seen in dark environment
crt (g=2.2, l=80, b=1, k=0.02, a=60 )
CRT monitor seen in dim environment
The parameters in the parenthesis are the same as for the gamma-gain-black-ambient model explained above.
Lookup-table
lut = <file>
This is the most accurate specification of the display response function, but requires measuring it with a luminance meter. The lookup table should account also for ambient light, so that it is recommended to use the luminance meter that can measure screen luminance from a distance, such as Minolta LS-100 (as opposed to those that use rubber tube touching a display that eliminates the influence of ambient light). The <file> must be a comma-separated text file in a format (CSV) with two columns: first column represents pixel values (from 0.0 to 1.0) and the second physical luminance in cd/mˆ2. Both the pixel value and the luminance should increase in each raw.
EXAMPLES
pfsin
barbara.jpg | pfsdisplayfunction -l -d pd:crt -v | pfsout
barbara_crt.hdr
Convert barbara.jpg image from pixel values to a luminance map of the image shown on a CRT monitor and store the map as an HDR image.
SEE ALSO
pfsgamma (1) pfstmo_mantiuk08 (1)
BUGS
Please report bugs and comments to the pfstools discussion group (http://groups.google.com/group/pfstools).