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pfsview(1) [suse man page]

pfsview(1)						      General Commands Manual							pfsview(1)

NAME

       pfsview - Viewer for high-dynamic range images in pfs format

SYNOPSIS

       pfsview [--window_min <log_lum>] [--window_max <log_lum>]

DESCRIPTION

       pfsview	is  a QT application for viewing high-dynamic range images. It expects pfs stream on the standard input and displays the frames in
       that stream one by one.

       pfsv script can be more convienent to use if hdr images are to be displayed without any prior processing.

DYNAMIC RANGE WINDOW

       To show high-dynamic range data on a low-dynamic range monitor, pfsview uses concept of a dynamic range window. The dynamic range window is
       the  highest  and  lowest  value that should be mapped to black and white pixel. Values above or below the window are clipped (see clipping
       methods below). The dynamic range window is displayed in pfsview as a blue area on the dynamic range scale (second toolbox from	the  top).
       The window can be moved, shrunk and expended using a mouse or a keyboard.

CLIPPING METHODS

       Currently, two clipping methods are available (see View menu):

       Simple clipping
	      The values above and below the dynamic range window are displayed as black or white.

       Color-coded clipping
	      The  values above the dynamic range window are displayed as yellow and below the window as green. This is helpful to see which parts
	      of the image do not fit into the selected dynamic range.

       Keep brightness and hue
	      This method tries to preserve brightness and hue while sacrificing color saturation when the colors exceed the RGB color gamut. Col-
	      ors are desaturated in the RGB color space towards the neutral color (D65) of the corresponding luminance.

MAPPING METHODS

       High-dynamic range data are usually better visualized using non-linear scale, for example a logarithmic or a power function. pfsview offers
       several such scales, shown in View menu. Gray-scale values for each mapping method are computed by the formulas:

       LINEAR: y = (x-min)/(max-min)

       GAMMA: y = [ (x-min)/(max-min) ]^gamma

       LOGARITHMIC: y = (log10(x)-log10(min))/(log10(max)-log10(min))

       where y is the gray-scale value after mapping, x is an input HDR value, min and max are lower and upper bounds of the dynamic range window.

OPTIONS

       --window_min <log_lum>

	      Lower bound of the values that should be displayed or minimum value of the dynamic range window. The value should be given in log_10
	      units, for example -1 if the lower bound should be 0.1 (10^-1).

       --window_max <log_lum>
	      Upper bound of the values that should be displayed or minimum value of the dynamic range window. The value should be given in log_10
	      units, for example -1 if the upper bound should be 0.1 (10^-1).

EXAMPLES

       pfsin memorial.hdr | pfsview
	      See the memorial image.

       pfsv memorial.hdr
	      The same as above, but using the utility script 'pv'.

SEE ALSO

       pfsv(1) pfsin(1)

BUGS

       Zomming in may sometimes show artifacts.

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

																	pfsview(1)

Check Out this Related 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)
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