Previous: DISPMANY, Up: Displaying Sphere Drawings SLU — Gamma Correction for E&S PS 340

SLU (Set LookUp) will set the color lookup tables for the Evans & Sutherland Picture 340. The color lookup tables are used to adjust for the scaling of intensities for each of three primary colors. In our eyes, the lower end of the scales are too dark, so SLU provides a smooth mechanism for shifting the values. The function used is

1/b f(x) = k x

where x is the position in the color lookup table and f(x) gives the adjusted value. k, which depends on b, is adjusted to correctly normalize f(x). The program asks for b. DI340 sets b to 1.

N.B. This program works only a VAX/VMS computer.