[mixedCase]

That sounds like an edge case that should just be accounted for in finder. lgnoring for certain file sizes is a fast solution that can be expanded upon as your thumbnailing programs grow in efficiency and improve their handling of low-IO situations or large files.

[BugsJustFindMe]

Should! But apparently isn't. In fact, nearly every image viewing/accessing program assumes that your image content will just happily fit entirely in available RAM after decompression and doesn't bother with things like live tiling.

[coldtea]

>In fact, nearly every image viewing/accessing program assumes that your image content will just happily fit entirely in available RAM after decompression

Sounds like a totally reasonable assumption, for 99.9% of the cases (including graphic designers).

[BugsJustFindMe]

Absolutely, and the pervasiveness of that mindset leads to things like tearing through swap and grinding the computer to a halt because the user clicked on a random file. It doesn't take supergenious or paranormal powers to realize that files might be arbitrarily large. Engineers mostly just fail to care.