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)