can't load big image of 17068x17068

[nothings]

I have same error with a big image of 17068x17068 with format 32 bits.
The error message is "too large".

Originally posted by @aribot-hrv in #752 (comment)

[nothings]

See also #672.

stb_image won't read images which take up more than 1 GB of memory because it was written using 32-bit integers; 1 GB is 2^30.

A 16384x16384 image with 4 channels will take up exactly 1 GB, so 17068 x 17608 is larger than that.

This should probably be fixed, but it's a huge endeavour.

@rygorous As a short-term workaround, can we bump the limit up to 2^31 on 64-bit machines, or do you remember if there's something in the code that makes 2^30 the real limit?

[nothings]

moving this into #672.