Rududu codec : new test version

[LigH]

*Cough* - blowing the dust off this thread...

Seems that there is no further development since september; how bad, this could have been such a great project.

[rududu author]

well, not so dead, just "sleeping".
I will continue the developpement, but I have no time at the moment.

Nicolas

[LigH]

So, at least, thank you for this "sign of life", and best whishes!

[unmei]

hey yeah, thanks for clearing the situation, nicolas! Take your time, i'm just glad you haven't given up :)

[pieter1976]

I think a Wavelet is a kind of interpolation.

Not a very good one.

I wonder if better compression ratio's could be achieved using better interpolations.

http://audio.rightmark.org/lukin/graphics/resampling.htm

This is dynamic interpolation using edge enhancement.

[d'Oursse]

Originally posted by pieter1976
I think Wavelet is a kind of interpolation.
no, not at all.

interpolation is getting information with few data (you have the values of a function at points 0 and 1. You want a approximated value of this function for all real numbers between 0 and 1, for example)

wavelets (more precisely a wavelet basis) are a way to describe information (a function) at different levels of detail (sorry for this very short description).

If you are interested, look at books and papers of Y. Meyer, S. Mallat, I. Daubechis, A. Cohen and so many other authors about wavelets.

[pieter1976]

This is what i know about wavelets

It first uses a image that is smaller than the size of the origenal.

second the resolution is increased.

pixels are smoothed

detail is added

resolution is increased

pixels are smoothed

detail is added

enz..

enz..

the part of increasing the resolution and smoothing the pixels is called interpolation.

please tell me if I am wrong.

[Lefungus]

You're wrong.
It'll be too tedious to explain wavelets on a forum in a foreign language. Like D'Oursse, i suggest you grab a book on the subject. There are also many sites on the subject that may interest you :)

[pieter1976]

I have looked at several paper and even made a computer program in Delphi to test it and it gave similar results.

these are the basics

You use four pixels

12
34

Than calculate the everage of the four pixels(low resolution part)
after that calculate the high frequenties (detail information)

Do this in a recursive way

The high frequenties values are compressed by losing bits.

http://www.acm.org/crossroads/xrds6-3/sahaimgcoding.html

[Lefungus]

Originally posted by pieter1976

http://audio.rightmark.org/lukin/graphics/resampling.htm

This is dynamic interpolation using edge enhancement.

This is off topic, but i would love to have a smart-edge resize avisynth filter :)

[pieter1976]

yes that would be great. It must be posible to make dvd resolution frames out of VHS frames and still have a good quality.

[Lefungus]

The authors doesn't seem to offer some source code though :/

[pieter1976]

I have made a smartedge filter but it is very slow and i don't know how to make one for a program like virtualdub.
It also needs some more work to be ready.

Does someone know how?

maybe a thread on this subject should be started.

[Selur]

yeah, a (avisynth/directshow) resizer with this might be cool, but without any sourcecode or at least a paper that discribes it,...

hoping for rududu author to find some time to develop rududu a bit ;) (I like the codec and like LigH I think it is a great project)

Cu Selur

[kilg0r3]

Hey Nicolas,

I don't know if you are still listening, but what about joining your project with that of the BBC?

[superdump]

Hmm, over a year on and no more news? Even if it's just another - "I'm still alive, I have no time to work on it and I'm unlikely to in the future. Here's the source code."

[General Lee D. Mented]

Hmm, over a year on and no more news? Even if it's just another - "I'm still alive, I have no time to work on it and I'm unlikely to in the future. Here's the source code."

Boo!!

[Sirber]

already 1 year? :(

[superdump]

Boo!!Hello there GLDM. How are you doing? Any progress with WARP? :)

[issa]

I have looked at several paper and even made a computer program in Delphi to test it and it gave similar results.

these are the basics

You use four pixels

12
34

Than calculate the everage of the four pixels(low resolution part)
after that calculate the high frequenties (detail information)

Do this in a recursive way

The high frequenties values are compressed by losing bits.

http://www.acm.org/crossroads/xrds6-3/sahaimgcoding.html

You can said decoding process is kind of interpolation. However, in interpolation, you are guessing the thing in between, but the in wavelet, you alway have the orignal (sort of) information of the gap.

[General Lee D. Mented]

Hello there GLDM. How are you doing? Any progress with WARP? :)

Nope, not really. Been too busy with moving, working, getting married, etc. I did eventually find the overflow bug, but I've never gone back and made any changes or improvements. I just haven't had the time and enthusiasm to bother.

[General Lee D. Mented]

You can said decoding process is kind of interpolation. However, in interpolation, you are guessing the thing in between, but the in wavelet, you alway have the orignal (sort of) information of the gap.

Well the thing is, with interpolation you're assuming that the intermediary values have a linear relationship to the sample points. With a wavelet or DCT system, you encode your data as the parameters to generate functions that fit the sample points. So instead of just guessing the middle, you guess whatever your function graph produces with the parameters you have available on decode. The problem is, if your function isn't a good match for your data, your quality/size ratio sucks, and it's more compute intenseive than just simple averaging.

I've got a compromise system design for this BTW, never implemented it.