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Radiance 3.5 User Manual

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falsecolor (1)

NAME

falsecolor - make a false color RADIANCE picture

SYNOPSIS

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

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 nits, where dark areas are blue and brighter areas move through the spectrum to red. A different scale can be given with the -s option. 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 "Nits", 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 -n option can be used to change the number of contours (and corresponding legend entries) from the default value of 8.
The -e option causes extrema points to be printed on the brightest and darkest pixels of the input picture.
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.pic
To create a logarithmic contour plot of illuminance values on a Radiance image:
rpict -i -vf default.vp scene.oct > irrad.pic
rpict -vf default.vp scene.oct > rad.pic
falsecolor -i irrad.pic -p rad.pic -cl -log 2 -l Lux > lux.pic

AUTHOR

Greg Ward

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)
http://www.schorsch.com/en/software/rayfront/manual/htmlman/falsecolor.html
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