1) IMO pointless to put an emphasis on extreme decompression speed but not show numbers against JPEG even
2) BCx essentially does the same codebooking/paletting but more efficiently by allowing you to interpolate between two palette entries for an even larger compression
This seems like straining the definition of "compression". We have a delta-coding filter and then palettization? That's it?
Edit: I should say, I find it surprising (but cool) that it apparently works so well. I would have expected errors to accumulate since the decoder has to un-delta-code. I saw mention of Floyd-Steinberg dithering and presumably that's what it's for; seems hard to get it working across multiple colour axes simultaneously, but the complexity is all in the encoder, so.
Worth noting that something perf-optimized for RP2350 is almost certainly not going to be optimal on a modern desktop-class core (with deep pipelines and wide ILP/SIMD).
This reminds me a bit of Amiga HAM. Similar horizontal fringing.
I guess you could also call Amiga's HAM graphics mode a compression method. Getting 12-bit (4096 colors) with just 6 input bits, with the original Amiga chipset, often called as "OCS".
Or later 262144 colors with 8 input bits, with the AGA chipset.
I'm impressed. The imbalance between encoding and decoding speeds seems a useful strategy when you are building special purpose hardware and software applications.
It seems if you're making a central source of data that is able to tolerate a much slower write process versus a quick read process that this approach can be advantageous.
Maybe using this core method in a problem space which maps to the radio/signal broadcast process of many receivers but a central source of truth.
I can imagine if you had an information base that changed slowly or which was pre-processed in a batch fashion, that it could use this method.
It doesn't even need for the central data to be decoded into a graphical image.
I think this radio model could map the problem space for a centralized system that maintained a list of items and their prices which needed to be broadcast to the retail outlets on a regular basis.
Or a common cache storage to make some complex data manipulation calculations centrally performed available to a large number of satellites who just need the end results but do not have the need to do local calculation.
2) BCx essentially does the same codebooking/paletting but more efficiently by allowing you to interpolate between two palette entries for an even larger compression
Edit: I should say, I find it surprising (but cool) that it apparently works so well. I would have expected errors to accumulate since the decoder has to un-delta-code. I saw mention of Floyd-Steinberg dithering and presumably that's what it's for; seems hard to get it working across multiple colour axes simultaneously, but the complexity is all in the encoder, so.
I guess you could also call Amiga's HAM graphics mode a compression method. Getting 12-bit (4096 colors) with just 6 input bits, with the original Amiga chipset, often called as "OCS".
Or later 262144 colors with 8 input bits, with the AGA chipset.
I think this radio model could map the problem space for a centralized system that maintained a list of items and their prices which needed to be broadcast to the retail outlets on a regular basis.
Or a common cache storage to make some complex data manipulation calculations centrally performed available to a large number of satellites who just need the end results but do not have the need to do local calculation.