/usr/share/radiance/sf.cal is in radiance-materials 4R1+20120125-1.
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 14 15 16 17 18 19 20 | {
Calculation of contrast-based scalefactor
8/17/93
Input: ex = picture exposure
or: Lwa = world adaptation luminance
Output: sf = scalefactor for display
adj = corresponding exposure adjustment
Optional Inputs: Ldmax = maximum display luminance
Lda = display adaptation luminance
}
Lwa = WE*.5/ex;
Ldmax = 120;
Lda = Ldmax/2;
sf = ((1.219 + Lda^.4)/(1.219 + Lwa^.4))^2.5 / Ldmax;
adj = WE*sf/ex;
|