Hi all, I observed this with 1.5.2svn.
Scaling on screen by a "nice" number like 50% or 25% gives better scrolling performance versus other factors. I think in any case the scaled image should be computed once and cached or at least held in a buffer for scrolling. No decimal point is allowed in the Qt4 dialogue box, so I can't enter 12.5%. Based on the above, that's the number I wanted :) In general, on-screen scaling in LyX is still pretty ugly compared to most software. In LyX it seems to scale down (decimate) by grabbing every Nth pixel, so you get horrible aliasing, especially with narrow line art where lines will be broken or disappear altogether. What would look much better is low-pass filtering prior to decimation, which would eliminate the above aliasing problems. If nobody else puts their hand up, I might work on this some day, but currently I have other obligations :) I have a background in image processing and I would certainly offer advice to whoever works on it. Have fun, Darren
