pfsabsolute(1) [suse man page]

pfsabsolute(1)						      General Commands Manual						    pfsabsolute(1)

NAME

       pfsabsolute - Convert luminance in images to absolute measure

SYNOPSIS

       pfsabsolute <dest Y> [<src Y>] [--verbose] [--help]

DESCRIPTION

       pfsabsolute  applies  all necessary operations to convert an image from relative luminance (tag LUMINANCE is RELATIVE) or display-dependent
       luma (tag LUMINANCE is DISPLAY) to absolute luminance values. When the luminance in an image is absolute (tag LUMINANCE set  to	ABSOLUTE),
       the  Y  channel represents physical luminance in cd/m^2. Absolute luminance levels are useful for some tone mapping algorithms and also for
       image or video compression.

       The argument <dest Y> denotes the level of luminance that relative luminance <src Y> should be rescaled to. The luminance is in fact multi-
       plied  by  the  ratio <dst Y>/<src Y>. <src Y> is normally relative luminance checked with pfsview in the spot where the absolute luminance
       <dest Y> is measured, known or guessed. If <src Y> is omitted, the value 1 is assumed, so <dest Y> is just a scaling factor.

       In case if display-depended luma (tag LUMINANCE is DISPLAY), the inverse gamma correction is applied (assuming sRGB color space).  In  such
       case <dest Y> is usually the maximum luminance of a display (e.g. 80 cd/m^2).

       This command always sets LUMINANCE tag to ABSOLUTE.

EXAMPLES

       pfsin memorial.hdr | pfsabsolute 20 0.04 | pfsview

	      Multiply	luminance  in  memorial  image, so that relative luminance 0.04 becomes 20 cd/m^2. Normally, the value 0.04 is check using
	      pfsview in the spot, where the absolute luminance (which equals in this case 20 cd/m^2) is known.

       pfsin lena.png | pfsabsolute 80 | pfsview

	      Convert lena image from sRGB color space to absolute XYZ, assuming maximum luminance of the monitor 80 cd/m^2.

SEE ALSO

       pfsgamma(1) pfsinppm(1)

BUGS

       Please report bugs and comments to Rafal Mantiuk <mantiuk@mpi-sb.mpg.de>.

																    pfsabsolute(1)

pfsinimgmagick(1)					      General Commands Manual						 pfsinimgmagick(1)

NAME

       pfsinimgmagick - Load images or frames using ImageMagick++ library

SYNOPSIS

       pfsinimgmagick (<file> [--linear] [--absolute <max_lum>] [--frames <range>] [--skip-missing])  [<file>...]

DESCRIPTION

       This  command  can  load  images or frames in the multitude of image formats supported by the ImageMagick library. This includes but is not
       limited to: BMP, JPG, PNG, GIF, EPS, TIFF, DPX. See the manual page of ImageMagick for the full list of available formats.

       pfsinimgmagick reads images or frames from files and writes pfs stream to the Standard Output. The pfs stream is usually piped  to  another
       program for further processing. To detect the format automatically based on the extension, use pfsin command.

       The  output  of	pfsinimgmagick	is scaled to 0-1 range, unless '--absolute' option is specified. By default, the 'LUMINANCE' tag is set to
       'DISPLAY' contents. Using the '--linear' switch you can force the inverse sRGB transformation to provide linear	data.  In  this  case  the
       'LUMINANCE' tag is set to 'RELATIVE' contents. '--absolute' switch can be used to convert pixels to absolute luminance values.

       This command handles properly 'alpha' channel (transparency) stored in images.

       Each file can contain a %d pattern, which is substituted with frame numbers. The pattern has the same syntax as C printf command. For exam-
       ple, you can use %04d to make the frame number four digit with proceedings zeros. You can select the frames  using  the	following  options
       (the options must be always given after the file name):

       --frames <range>
	      Range is given in mathlab / octave format:

	      startframe:step:endframe

	      Frame  numbers  start  with startframe (default 0), are increased by step (default 1) and stop at endframe You can skip one of those
	      values, for example 1:100 for frames 1,2,...,100 and 0:2: for frame 0,2,4,... up to the last file that exists.

       --skip-missing
	      Skip up to ten frames in a row if corresponding files are missing. Otherwise the program stops reading sequence at  the  first  file
	      that  does not exists. This switch does not apply to the first frame in a sequence. This switch can be useful if there is a rendered
	      animation where some of the frame has not been generated.

       --linear, -l
	      Converts pixel values to linear luminance (XYZ), assuming the sRGB color	space  for  the  input	image.	The  maximum  pixel  value
	      (255,255,255) is mapped to Y=1. LUMINANCE tag is set to RELATIVE.

       --absolute <max_lum>, -a <max_lum>
	      --absolute  converts  pixel values to an absolute linear luminance (XYZ), that is the color space, in which channel Y contains lumi-
	      nance given in cd/m^2. The sRGB color space is assumed for the input image. The maximum  pixel  value  (255,255,255)  is	mapped	to
	      Y=<max_lum>.  <max_lum>  is  typically  set  to  80 [cd/m^2] for a CRT monitor. LUMINANCE tag is set to ABSOLUTE. --absolute process
	      images almost the same as --relative, but additionally it scales all pixels by <max_lum>.

EXAMPLES

       pfsinimgmagick frame%04d.dpx --frames 0:10 | pfsview

	      Read frames from files frame0000.dpx, frame0001.dpx, ..., frame0010.dpx and show them using pfsview.

BUGS

       pfsinimgmagick can not read frames from the Standard Input.

       Please report bugs and comments on implementation to the discussion group http://groups.google.com/group/pfstools

SEE ALSO

       pfsin(1), pfsout(1) ImageMagick(1)

																 pfsinimgmagick(1)