<div dir="ltr"><div>Hello,<br></div><div><br></div><div>I forgot in my last reply that my DWT implementation can be speed up, for example I'm doing for now:</div><div><br></div><div> for (;_X1<_E_;_X1++,_RES+=2) //dilatation<br> { <br> _RES[0]=_X1[0]<<3;<br> _RES[1]=(_X1[1]+_X1[0])<<2;</div><div> }</div><div><br></div><div>then</div><div><br></div><div> for (;_X2<_E_;_X2++,_RES+=2) //details<br> {<br> _RES[0]-=(_X2[1]+_X2[0])<<1;<br> _RES[1]+=6*_X2[1]-_X2[2]-_X2[0];<br> }</div><div><br></div><div>whereas I can do in one faster step:</div><div><br></div><div> for (;_X1<_E_;_X1++, _X2++,_RES+=2)<br> {<br> _RES[0]=_X1[0]<<3 - (_X2[1]+_X2[0])<<1;<br> _RES[1]=(_X1[1]+_X1[0])<<2 + 6*_X2[1]-_X2[2]-_X2[0];<br> }</div><div><br></div><div>In these conditions, my implementation seems as fast as the lifting scheme, they are doing exactly the same things in two different ways, but similar speed ways.</div><div><br></div><div>So I think we can keep my DWT implementation in the NHW codec!!!</div><div><br></div><div>I have heard Monty that I must do (interesting) technology demonstrations as part of the NHW Project story, but I don't know what to start, and I also lack the graphical design capabilities...</div><div><br></div><div>Monty, a second answer would be very welcome?!</div><div><br></div><div>Many thanks!</div><div>Cheers,</div><div>Raphael<br></div><div><br></div><div><br></div><div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2017-09-01 18:12 GMT+02:00 Raphael Canut <span dir="ltr"><<a href="mailto:nhwcodec@gmail.com" target="_blank">nhwcodec@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div><div><div><div><div><div><div>Hello,<span class="gmail-"><br><br>> What references do your versions draw from?<br><br></span></div>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?-</div><div><br></div>For the entropy coding, I think there is new things.<br>For the multistage residual coding, this is not new, but I have never seen it applied to an image codec...<br></div>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.<br></div>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.<br><br></div>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?<br><br></div>The other advantage of the NHW codec is that it is royalty- and patent- free.Do you see at first some patented technology used?<br><br></div>Cheers,<br></div>Raphael<br><div><div><div><div><div><div><div><br><br></div></div></div></div></div></div></div></div><div class="gmail_extra"><br><div class="gmail_quote"><span class="gmail-">2017-08-30 10:16 GMT+02:00 <span dir="ltr"><<a href="mailto:xiphmont@xiph.org" target="_blank">xiphmont@xiph.org</a>></span>:<br></span><div><div class="gmail-h5"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi Raphael,<br>
<span><br>
On Fri, Aug 25, 2017 at 2:30 PM, Raphael Canut <<a href="mailto:nhwcodec@gmail.com" target="_blank">nhwcodec@gmail.com</a>> wrote:<br>
<br>
> I'll see what Monty will do on his side (and when he has time), but he also<br>
> told me that the NHW codec has merits but there must be an effort to<br>
> demonstrate them.<br>
<br>
</span>Well, if you want to pursue a collaborative project, you need to<br>
attract others to work on it. Perhaps 'demo' is the wrong word... I'd<br>
say the project needs to have a story, and a demonstration of the<br>
technology is part of what makes the story concrete.<br>
<span><br>
> But it is not so evident to demonstrate them, because the NHW codec performs<br>
> bad on all metrics because it modifies image to give it more neatness (this<br>
> also includes a slight denoising)... For speed, the NHW codec is written in<br>
> plain C code, there are no C optimization, no SIMD optimization, no<br>
> multithreading, whereas the other codecs (x265,VP9,x264,WebP,...) have them<br>
> and are highly optimized, so time/speed comparison will not be fair...<br>
<br>
</span>Optimization at this stage of development is misplaced. You should<br>
have a good idea of the complexity bounds-- this is what other<br>
engineers care about-- but so long as you can demonstrate that your<br>
approach does something unique and useful in a way that draws<br>
interest, that's what you need.<br>
<span><br>
> Then there are innovations in the NHW codec: like a new fast wavelet<br>
> transform, a multistage residual coding, 3 new entropy coding schemes and<br>
> other things like for example interesting pre- and post- processing based on<br>
> a laplacian kernel, a feedback correction,etc...<br>
<br>
</span>All these things have been done before... how are your approaches<br>
unique? What references do your versions draw from? Build on? One<br>
reason to be familiar with (and use the language) of the state of the<br>
art is to provide a shared context and terminology in which others can<br>
understand what you're doing.<br>
<span><br>
> Monty told me :"If you don't have access to web space you can use for<br>
> documenting and advertising the project, we can certainly offer that."<br>
<br>
</span>Absolutely.<br>
<span><br>
> Are you interested in documentation of the innovations of the NHW codec? As<br>
> I am still very busy (but this will change), do some of you would like to<br>
> make these demonstrations?<br>
><br>
> So to finish, I think it's a great deal that Xiph.org proposes!!!, if you<br>
> want more of this collaboration, want to help in the development,<br>
> documentation, demonstration of the NHW Project, do not hesitate to show up<br>
> on the forum.<br>
><br>
> Many thanks again to Xiph!, hope this will materialize in the next months.<br>
<br>
</span>Good wishes to you too!<br>
<br>
Cheers,<br>
Monty<br>
<br>
><br>
> Cheers,<br>
> Raphael<br>
><br>
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><br>
</blockquote></div></div></div><br></div>
</blockquote></div><br></div></div></div></div></div>