/usr/share/radiance/picdiff.cal is in radiance-materials 4R0+20110410-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 | {
Compute difference between luminance of two images.
Display towards red where first image is brighter,
and towards blue where second image is brighter.
29 August 1991
}
l1=li(1); l2=li(2);
avg=(l1+l2)/2;
dif=(l1-l2)/2;
ro=avg+dif;
go=avg-dif*dif/2;
bo=avg-dif;
|