A new PNG spec

(www.programmax.net)

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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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1. bla3 ◴[25 Jun 25 16:12 UTC] No.44378924[source]▶

>>44375919 #

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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2. adzm ◴[25 Jun 25 16:23 UTC] No.44379059[source]▶

>>44378924 (TP) #

Only downside is that webp lossless requires RGB colorspace so you can't, for example, save direct YUV frames from a video losslessly. AVIF lossless does support this though.

3. mchusma ◴[25 Jun 25 17:16 UTC] No.44379693[source]▶

>>44378924 (TP) #

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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4. ProgramMax ◴[25 Jun 25 17:38 UTC] No.44379884[source]▶

>>44378924 (TP) #

WebP maxes at 8-bit per channel. For HDR, you really need 10- or 12-bit.

WebP is amazing. But if I were going to label something "state of the art" I would go with JPEGXL :)

5. Inityx ◴[25 Jun 25 20:41 UTC] No.44381619[source]▶

>>44379693 #

Asset pipelines for media creation benefit greatly from better compression of lossless images and video

6. account42 ◴[26 Jun 25 08:55 UTC] No.44385510[source]▶

>>44378924 (TP) #

Last I checked cwebp does not preserve PNG color space information properly so the result isn't actually visually lossless.

7. kbolino ◴[26 Jun 25 14:54 UTC] No.44388048[source]▶

>>44379693 #

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.

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