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A new PNG spec

(www.programmax.net)
624 points bluedel | 1 comments | 24 Jun 25 13:01 UTC | HN request time: 0.244s | source
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ksec ◴[25 Jun 25 11:10 UTC] No.44375919[source]▶
It is just a spec on something widely implemented already.

Assuming Next gen PNG will still require new decoder. They could just call it PNG2.

JPEG-XL already provides everything most people asked for a lossless codec. If there are any problems it is its encoding and decoding speed and resources.

Current champion of Lossless image codec is HALIC. https://news.ycombinator.com/item?id=38990568

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bla3 ◴[25 Jun 25 16:12 UTC] No.44378924[source]▶
WebP lossless is close to state of the art and widely available. It's also not widely used. The takeaway seems to be that absolute best performance for lossless compression isn't that important, or at least it won't get you widely adopted.
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mchusma ◴[25 Jun 25 17:16 UTC] No.44379693[source]▶
I don't know that i have ever used jpg or png lossless in practical usage (e.g. I don't think 99.9% of mobile app or web usecases are for lossless). WebP lossy performance is just not worth it in practice, which is why WebP never took off IMO.

Are there usecases for lossless other than archival?

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1. kbolino ◴[26 Jun 25 14:54 UTC] No.44388048[source]▶
I definitely noticed when the Play Store switched to lossy icons. I can still notice it to this day, though they did at least make it harder to notice (it was especially apparent on low-DPI displays). Fortunately, the apps once installed still seem to use lossless icons.

A lot of images should be lossless. Icons/pictograms/emoji, diagrams and line drawings (when rasterized), screenshots, etc. You can sometimes get away with large-resolution lossy for some of these if you scale it down, but that doesn't necessarily translate into a smaller file size than a lossless image at the intended resolution.

There's another problem with lossy images, which is re-encoding. Any app/site that lets you upload/share an image but also insists on re-encoding it can quickly turn it into pixelated mush.