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Oswald
Registered: Apr 2002
Posts: 5017 |
koala otpimizing
Hi Everyone,
I know there's a c64 tool out there that helps with optimizing koala pictures for packing, but no idea what it is called. Anyone knows?:) Timanthes would do the job for me aswell with its nibble swapper tool, but is there a way to load/save a native c64 koala format picture with it ? *.prg doesnt works, what format does it expect to be .prg anyway ?:) |
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Oswald
Registered: Apr 2002
Posts: 5017 |
I'm coming here for the 4th time, checked CJ's release also a few times, am I the only one not finding the info on what is the compression scheme in there ? :) |
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ChristopherJam
Registered: Aug 2004
Posts: 1378 |
I just left a comment on the release with a rough outline. |
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Fungus
Registered: Sep 2002
Posts: 616 |
Quote: Quoting SpartaSPOT doesn’t change the cleanliness of the koala and outputs standard koala but it can also create other formats such as the combined color RAM nibbles if that fits one’s needs better. :)
Yea, just tested myself as well and indeed, I was just hoping combined nibbles would be the main reason why I'm trailing behind :)
Quoting Funguspico 1.3+dali = 5980
Fungus Handiwork Wins! \o/
Actually that one was S!R handywork. |
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ChristopherJam
Registered: Aug 2004
Posts: 1378 |
Quote:the second best option after putting a FungusS!R in every home |
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Oswald
Registered: Apr 2002
Posts: 5017 |
Quote: I just left a comment on the release with a rough outline.
thanks:) |
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Sparta
Registered: Feb 2017
Posts: 38 |
SPOT 1.3 WIP + Dali:
Untitled/Floris: 7343
Song of the Sunset/Mermaid: 5145
Short Circuit/Karen Davies: 5974
The total gain is 28 bytes. Not a lot, but at least it beats S!R's handywork. ;P |
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ThunderBlade
Registered: Jan 2002
Posts: 75 |
Can you add some info on what SPOT actually does to achieve its great results? Or is there a general article about C64 multicolor optimizing? |
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Fungus
Registered: Sep 2002
Posts: 616 |
I don't know of any article, but my work flow is to remove unused bits and colors. Then sort most used colors into the color memory and then try to get the rest of the colors into the other map and then fill the unused with colors to create the longest runs I can.
It might be better to optimize for the longest bitpair runs, but I don't know how you would go about such a thing because of how the bitmap is laid out, perhaps that is what cjam is doing.
People often forget to and the color memory with #$0f. |
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Sparta
Registered: Feb 2017
Posts: 38 |
Assuming that people typically use LZ-based compression (except CJam, of course), Koala optimization boils down to the bin packing problem. SPOT rearranges the colors using something that is probably best described as a best-fit-decreasing algorithm. I have a few more optimization steps but as it turns out they still need some fine tuning as they only work in select cases. E.g. I got Mermaid’s pic down to 5137 bytes with Dali but the other two got worse. |
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Fungus
Registered: Sep 2002
Posts: 616 |
I suppose you could do some kind of statistical analysis of equal sequences over equal bytes of a given length and try to optimize for that. I would think repeating bytes of 8 would give better results than runs in the color map, if that's possible to do. |
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