06-08-11 - Tech Todos

Publicly getting my thoughts together :

1. Oodle. Just finish it! God damn it.

2. JPEG decoder. I got really close to having this done, need to finish it. The main thing left that I want to do is work on the edge-adaptive-bilteral filter a bit more; currently it's a bit too strong on the non-artifact areas, I think I can make it more selective about only working on the ringing and blockiness. The other things I want are chroma-from-luma support and a special mode for text/graphics.

3. Byte-wise LZ with optimal parse. This has been on my list for a long time. I'm not really super motivated though. But it goes along with -

4. LZ string matcher test. Hash tables, hash->list, hash->bintree, hash->MMC, suffix trees, suffix arrays, patricia tries, etc. ? Would be nice to make a thorough test bed for this. (would also help the Oodle LZ encoder which is currently a bit slow due to me not spending any time on the string matcher).

5. Cuckoo hash / cache aware hash ; I did a bunch of hash testing a while ago and want to add this to my tests. I'm very curious about it, but this is kind of pointless.

6. Image doubler / denoiser / etc ; mmm meh I've lost my motivation for this. It's a big project and I have too many other things to do.

7. Make an indy game. Sometimes I get the craving to do something interactive/artistic. I miss being able to play with my work. (I also get the craving to make a "demo" which would be fun and is rather less pain in the butt than making a full game). Anyhoo, probably not gonna happen, since there's just not enough time for this.

ADDENDUM : some I forgot :

8. Finish my video codec ; I still want to redo my back end coder which was really never intented for video; maybe support multiple sizes of blocks; try some more perceptual metrics for encoder decision making; various other ideas.

9. New lossy image codec ; I have an unfinished one that I did for RAD, but I think I should just scrap it and do the new one. I'm interested in directional DCT. Also simple highly asymetric schemes, such as static classes that are encoder-optimized (instead of adaptive models; adaptive models are very bad for LHS). More generally, I have some ideas about trying to make a codec that is more explicitly perceptual, it might be terrible in rmse, but look better to the human eye; one part of that is using the imdiff metrics I trained earlier, another part is block classification (smooth,edge,detail) and special coders per class.


Anonymous said...

Personally, I'd love to see your take on byte-wise LZ with optimal parsing.

won3d said...

I spent a few days a few weeks ago on cache-aware/cuckoo hashing. I think there's some simple heuristics for doing things cache-aware, but I'm cooling to the idea of cuckoo hashing. It supports very high load factors, but average probing still has a bad knee.

old rants