I thing the endgame is lossless PNG with 16bit color components with basic compression like gzip or at best bzip2. Or a format without the weirdness of PNG 'line based loading' which is obsolete nowdays. The "expensive part", apart from the compression algorithm, being the meta data storage without kludge.

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mrob 4 hours ago | parent | next [-]

>without the weirdness of PNG 'line based loading' which is obsolete nowdays

How? Line-based loading is a very simple way to exploit 2D spatial coherence. A 1D format like gzip loses this advantage for minimal gain in simplicity.

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pmarreck 4 hours ago | parent | prev | next [-]

I believe 7zip outdoes bzip2 these days along every metric

And lossless jpeg-xl exceeds your idea

	▲	ciupicri an hour ago \| parent \| next [-]
		7zip meaning what, LZMA (xz)?
	▲	dist-epoch an hour ago \| parent \| prev [-]
		and zstandard outdoes 7zip (LZMA)

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apopapo 4 hours ago | parent | prev [-]

These days I favour lossless WEBP instead of PNG. I often save around 30%~40% of file size compared to PNG, especially when the PNG is encoded with lots of bits per pixel (i.e 48 bits or 24 bits).

	▲	F3nd0 2 hours ago \| parent [-]
		I think that’s why they were advocating for gzip or bzip2 instead of just relying on PNG’s built-in compression.