[jmseight]

Hi,

This is exact what I did in the afternoon. But I replace all values < 4 with 4, and all values > 59 with 59. Sorry I was not more specific.

This made everything < 4 brightness completely black, and > 59 brightness completely white.

However, I think this is NOT the best result. Because after all black, it is black with 4 intensity.

I think a better way is to scale first, so the brightness values goes instead of 0~63 to -3~67. Then use the same dither table. This will make a smooth transition from all black to linear to all white.

Schematically, it is like this

A) original
     /
    /
   /
  /
 /
B) Cutoff (modify the dither table)
     __
     |
     /
    /
   /
__|
C) Scaling
       __
      /
     /
    /
   /
__/

Thanks,
James