[theora] NHW Project - news with Xiph.org

Raphael Canut nhwcodec at gmail.com
Fri Sep 1 16:12:25 UTC 2017


> What references do your versions draw from?

I think I made a mistake! In fact my DWT implementation is "implied" in the
lifting scheme, but it could be slower than the lifting scheme because it
does not use the lifting steps.So I think we can replace my DWT
implementation in the NHW codec by the classic lifting scheme! -Does the
lifting scheme patented?-

For the entropy coding, I think there is new things.
For the multistage residual coding, this is not new, but I have never seen
it applied to an image codec...
Feedback correction is not new, but I think it's old enough to be
patent-free.I also did not see it in an image codec.
Preprocessing (with a laplacian kernel) is interesting in the NHW codec,
because it retains the details, grain that would be normally washed out by
increased wavelet quantization.

There are also other processing in the NHW codec (all selected and
optimized for speed), so I will try to make a technology demonstration.A
little help from Xiph?

The other advantage of the NHW codec is that it is royalty- and patent-
free.Do you see at first some patented technology used?


2017-08-30 10:16 GMT+02:00 <xiphmont at xiph.org>:

> Hi Raphael,
> On Fri, Aug 25, 2017 at 2:30 PM, Raphael Canut <nhwcodec at gmail.com> wrote:
> > I'll see what Monty will do on his side (and when he has time), but he
> also
> > told me that the NHW codec has merits but there must be an effort to
> > demonstrate them.
> Well, if you want to pursue a collaborative project, you need to
> attract others to work on it.  Perhaps 'demo' is the wrong word... I'd
> say the project needs to have a story, and a demonstration of the
> technology is part of what makes the story concrete.
> > But it is not so evident to demonstrate them, because the NHW codec
> performs
> > bad on all metrics because it modifies image to give it more neatness
> (this
> > also includes a slight denoising)... For speed, the NHW codec is written
> in
> > plain C code, there are no C optimization, no SIMD optimization, no
> > multithreading, whereas the other codecs (x265,VP9,x264,WebP,...) have
> them
> > and are highly optimized, so time/speed comparison will not be fair...
> Optimization at this stage of development is misplaced.  You should
> have a good idea of the complexity bounds-- this is what other
> engineers care about-- but so long as you can demonstrate that your
> approach does something unique and useful in a way that draws
> interest, that's what you need.
> > Then there are innovations in the NHW codec: like a new fast wavelet
> > transform, a multistage residual coding, 3 new entropy coding schemes and
> > other things like for example interesting pre- and post- processing
> based on
> > a laplacian kernel, a feedback correction,etc...
> All these things have been done before... how are your approaches
> unique?  What references do your versions draw from?  Build on?  One
> reason to be familiar with (and use the language) of the state of the
> art is to provide a shared context and terminology in which others can
> understand what you're doing.
> > Monty told me :"If you don't have access to web space you can use for
> > documenting and advertising the project, we can certainly offer that."
> Absolutely.
> > Are you interested in documentation of the innovations of the NHW codec?
> As
> > I am still very busy (but this will change), do some of you would like to
> > make these demonstrations?
> >
> > So to finish, I think it's a great deal that Xiph.org proposes!!!, if you
> > want more of this collaboration, want to help in the development,
> > documentation, demonstration of the NHW Project, do not hesitate to show
> up
> > on the forum.
> >
> > Many thanks again to Xiph!, hope this will materialize in the next
> months.
> Good wishes to you too!
> Cheers,
> Monty
> >
> > Cheers,
> > Raphael
> >
> > _______________________________________________
> > theora mailing list
> > theora at xiph.org
> > http://lists.xiph.org/mailman/listinfo/theora
> >
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