P.P.S. I turned the compiler optimization settings to maximum and suddenly the lanczos resizing accelerated immensely, as if getting a good punt. I test it on two large pictures being resized to 1024x2048, and they, kind of, load in a blink of an eye now.

It was FPC 2.0.4 with -Op4 -Ou -O3 -Or (target Pentium 4, uncertaing optimizations on, maximum optimization, keep certain variables in registers). My CPU is Sempron (a renamed older version of Athlon XP).

One more reason to build Vampyre Imaging directly from sources