Cheng Chien-Wen

I am reading Jitter Tutorial Chapter 29 about jit.alphablend. In the example patch, "jit.op@op !- @val 255" is used for a "crossfade on a cell-by-cell basis". I cannot understand what it means.

I am reading Jitter Tutorial Chapter 29 about jit.alphablend. In the example patch, "jit.op@op !- @val 255" is used for a "crossfade on a cell-by-cell basis". I cannot understand what it means.
Could anyone explain a little bit more ?

what is "crossfade on a cell-by-cell basis" ?