pfsglview(1)						      General Commands Manual						      pfsglview(1)

NAME

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

SYNOPSIS

       pfsglview [--h] [--v]

DESCRIPTION

       pfsview	is  a  OpenGL/GLUT 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.

DYNAMIC RANGE WINDOW

       To show high-dynamic range data on a low-dynamic range monitor, pfsglview 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 pfsglview 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.

ZOOMING AND PANNING

       To zoom image, the mouse can be dragged in vertical direction with the left button pressed.  Pressing [space] button or pressing left mouse
       button above the statistic window (left-bottom corner) changes from zooming to panning modes and vice versa. To pan image, the mouse can be
       dragged in vertical and horizontal directions with the left button pressed.

POPUP MENU OPTIONS

       Zoom reset
	      Set default zoom parameters.

       Zoom in
	      Increase image (mouse dragging with left button pressed).

       Zoom out
	      Decrease image (mouse dragging with left button pressed).

       Increase exposure
	      Move dynamic range window into higher luminance values.

       Decrease exposure
	      Move dynamic range window into lover luminance values.

       Extend dynamic range
	      Extend dynamic range window.

       Shrink dynamic range
	      Shrink dynamic range window

       Low dynamic range
	      Set dynamic range window to <-1,1> range (log scale).

       Fit to dynamic range
	      Set dynamic range windo to minimum and maximum luminance of a given image.

       Choose channel
	      Change image data channel.

       Mapping method
	      Change mapping method (see below for details).

       Next frame
	      Display next image from the pipe.

       Previous frame
	      Display previous image from the pipe.

       Histogram
	      Switch on/off histogram window.

       Info   Switch on/off info window.

       Save&Quit
	      Send the visible LDR image (8-bits) to stdout and quit pfsglview.

MAPPING METHODS

       High-dynamic  range  data  are  usually	better visualized using non-linear scale, for example a logarithmic or a power function. pfsglview
       offers several such scales, shown in popup 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.

EXAMPLES

       pfsin memorial.hdr | pfsglview
	      See the memorial image.

       pfsin memorial.hdr | pfsglview | pfsout memorial.jpg
	      See the memorial image and save the clipped (8-bits) version to memorial.jpg (Save&Quit option from popup menu should be activated).

SEE ALSO

       pfsin(1)

       Please report bugs and comments to Radoslaw Mantiuk <radoslaw.mantiuk@gmail.com>.

																      pfsglview(1)