Comment by ChrisMarshallNY

Without getting too much into detail (because the people I worked for were really paranoid, and I don't want to give them agita), we used to build lookup tables "on the fly," sometimes, deep inside iterators.

For example, each block of pixels might have some calculated characteristics that were accessed by a hash into a LUT, but the characteristics would change, as we went through the image.

We'd do a "triage" run, where we'd build the LUT, then a "detailed" run, where we'd apply the LUT to the pixels.

It could get pretty hairy.