NAME

       falsecolor - make a false color RADIANCE picture

SYNOPSIS

       falsecolor [ -i input ][ -p picture ][ -cb | -cl | -cp ][ -e ][ -s scale ][ -l label ][ -n
       ndivs ][ -lw lwidth ][ -lh lheight ][ -log decades ][ -m mult ][ -pal palette ][  -r  redv
       ][ -g grnv ][ -b bluv ]

       falsecolor -palettes

DESCRIPTION

       Falsecolor  produces  a  false  color  picture for lighting analysis.  Input is a rendered
       Radiance picture.

       By default, luminance is displayed on a linear scale from 0  to  1000  cd/m2,  where  dark
       areas  are purple and brighter areas move through blue, green, red to yellow.  A different
       scale can be given with the -s option.  If the argument given to -s begins with an "a" for
       "auto,"  then  the maximum is used for scaling the result.  The default multiplier is 179,
       which converts from radiance or irradiance to luminance or illuminance,  respectively.   A
       different  multiplier  can  be  given  with -m to get daylight factors or whatever.  For a
       logarithmic rather than a linear mapping, the -log option can be used,  where  decades  is
       the number of decades below the maximum scale desired.

       A  legend  is produced for the new image with a label given by the -l option.  The default
       label is "cd/m2", which is appropriate for standard Radiance images.  If the -i option  of
       rpict(1) was used to produce the image, then the appropriate label would be "Lux".

       If  contour  lines  are  desired rather than just false color, the -cl option can be used.
       These lines can be placed over another Radiance picture using the -p option.  If the input
       picture is given with -ip instead of -i, then it will be used both as the source of values
       and as the picture to overlay with  contours.   The  -cb  option  produces  contour  bands
       instead of lines, where the thickness of the bands is related to the rate of change in the
       image.  The -cp option creates a posterization effect where colours are banded without the
       background  image  showing  through.   The  -n  option can be used to change the number of
       contours (and corresponding legend entries) from the default value of 8.  The -lw and  -lh
       options  may  be used to change the legend dimensions from the default width and height of
       100x200.  A value of zero in either eliminates the legend in the output.

       The -e option causes extrema points to be printed on the brightest and darkest  pixels  of
       the input picture.

       The -pal option provides different color palettes for falsecolor.  The current choices are
       spec for the old spectral mapping, hot for a thermal scale, and pm3d for  a  variation  of
       the  default  mapping, def.  A Radiance HDR image of all available palettes can be created
       with the -palettes option.  The remaining options, -r, -g, and -b  are  for  changing  the
       mapping of values to colors.  These are expressions of the variable v, where v varies from
       0 to 1.  These options are not recommended for the casual user.

       If no -i or -ip option is used, input is taken from the standard input.  The output  image
       is always written to standard output, which should be redirected.

EXAMPLES

       To create a false color image directly from rpict(1):

         rpict -vf default.vp scene.oct | falsecolor > scene.hdr

       To create a logarithmic contour plot of illuminance values on a Radiance image:

         rpict -i -vf default.vp scene.oct > irrad.hdr
         rpict -vf default.vp scene.oct > rad.hdr
         falsecolor -i irrad.hdr -p rad.hdr -cl -log 2 -l Lux > lux.hdr

AUTHOR

       Greg Ward
       Axel Jacobs (Perl translation and -pal options)

ACKNOWLEDGEMENT

       Work on this program was initiated and sponsored by the LESO group at EPFL in Switzerland.

SEE ALSO

       getinfo(1),  pcomb(1),  pcompos(1),  pextrem(1), pfilt(1), pflip(1), protate(1), psign(1),
       rpict(1), ximage(1)