RE: Misc Codec Questions....

>> Hi.
>>
>> First of all, can someone confirm if the behavior i'm getting with
>> the (2,2)
>> wavelet is the same (i,e: No bit growth)?
>
>You can see this by looking on the equation for the lowpass
>coefficient, it's simply a truncated (or rounded) weighted average of
>the neighbor coefficient e.g. (x_i + x_{i+1})/2 for the (1,1) wavelet.
>There is no bit growth.

Which i guess is good since you don't need 16 bits to cary around so it's
more memory efficient. I stil lhave to figure out why my SPHIT coder is
doing so bad with this wavelet.

Out of curiosity (and laziness i guess since i could check the code). What
approach does Tarkin take so far to code the wavelet bits?

>> Second question... Anybody know of any bit coding scheme that is more
>> memory
>> efficient and less computationally expensive than EZW or SPHIT? I
>> don't
>> really care of the encode time but the SPHIT architecture seems like
>> it
>> might be a bottleneck on the decode time also...
>
>For this purpose a Vector Quantizer (VQ) might be the best solution.
>Maybe you can reuse Vorbis' ones when you modify it to work on
>integers.

Ok, VQ is simple to implement so it could be a good idea to experiment. I'v
read the links that were posted by Marco. Lots of interesting reading and
things to think about.

Sebastien St-Laurent
[email protected]



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