Every once in a while, a PNG image that I put through the popular lossless optimization/reduction tools will no longer display in some clients. This is rare enough that I never dug into it or isolated the causes. Has anyone put together a knowledge base or some quick tips on how lossless PNG optimization can break image display (which might be bugs in the viewer, not the optimization tool)? I didn't find anything in Encode forums, and nothing pops up on Google (although this project is so fascinating).
I'll collect more data, and try to isolate which tool+viewer combos have problems. But if there's already a knowledge base on the different lossless optimization techniques and how they interact with some viewers, I'd love to know about it.
FYI, the info I have is limited, but here it is: Sometimes images won't display in the newish Microsoft Photos app on Windows 10 desktop. I often put images through FileOptimizer, which pipes together OptiPNG, pngwolf, AdvanceCOMP, etc, so it's hard to isolate the tool causing the issue (which might be MS Photos' fault, not the tool's). Maybe 1 out of 10, or fewer, images that go through this pipeline won't display in MS Photos. This could be an MS Photos bug – I'll try more clients to make sure. I've also seen issues in browsers, but I didn't collect the data back then.
Tangent question: Does maximum lossless optimization/reduction complicate the decoder's job or reduce the decoding/decompression rate (MB/sec)? In other deflate applications, like gzip, maximum compression imposes no penalty on decompression rate, but I'm not sure about everything going on with PNG encoding/decoding.