WARNING: Block error very high at ...

[gunta]

Hi, I'm getting lots of "WARNING: Block error very high at ..." messages and compression takes like 2 minutes when trying to compress a 1024x1024 PNG file.

Any suggestions?

[gunta]

This is the image:
http://s17.postimg.org/qw07lyicf/urps.png

[Mokosha]

This happens with the BPTC compressor -- it's worth investigating:

WARNING: Block error very high at <608, 252>: (20.09)
WARNING: Block error very high at <276, 736>: (20.49)

These errors are exceptionally high and likely have to do with either how we treat the measurement of alpha errors or actually dealing with compressed alpha blocks themselves.

That being said, here is the compressed output. Doesn't look too bad (although you may disagree. :))