What process does export as PNG layers use?

[nick123]

Images I'm testing with have a circuit board below clear acrylic, which evidently had a fair bit of dust. At realistic viewing size this is inconsequential, however I thought I'd test the importing as layers into PS and see if knocking out parts of the layers with the most infocus dust would resolve. Tiffs with transparency can be problematic and indeed did not import into PS 2020 with masks, so I tried PNGs instead. The result was quite different to the C4 process I had run, and also B84 that I tried after that. I noticed the PNGs are 8 bit which might explain the colour shift, but the dust was also barely evident. The PNG result image was more blurry in parts, but this isn't explained by the bit depth.

So I'm wondering, what processing is used when producing a PNG export as it does not correspond to results already produced?

diff-compare.png (301.23 KiB) Viewed 3603 times