similar to: NHW codec - progress

Hello, I don't have advanced on the NHW codec, but now, as a lot of people, I am following the AOMedia AV1 codec.Just a (late) update of my previous post, there won't be problem in AOM AV1 with the CABAC scheme, as the codec will use Daala's multi-symbol entropy coder and/or ANS.That's great! I have even read on the wiki page, that AV1 will use Daala's PVQ as quantization

Hello all, Just a quick message for those interested in the NHW Project.I realize that I have too little time to spend on the project currently and I feel that this year will be very important after 6-7 years for its success or not.I already had some few replies from some companies (and a major one), and they can not spend some time, spend some engineers on my work because there is no

Hello, For those interested, I have improved the entropy coding scheme for wavelet coeffs compression.This scheme is now more complete, it is also faster, the compression gain is around 50-100octets, I would have expected more..., but it is getting harder to save bits for this part.Update at http://nhwcodec.blogspot.com/ . Now the discussions on video compression will be certainly focused on the

Hello all, It's me again.Just a quick message to tell that I finally do not agree that HEVC (don't have tested AOM AV1 for now) is better than the NHW codec at mid compression. Last night, I dowloaded 30 images of Star Wars Rogue One on the web and I made another comparison with x265 (HEVC) for mid compression (-l2 to h2 settings for the NHW codec). Visually, I prefer the results of NHW

Hello, I have some progress for the NHW codec. I recently talked with a researcher that has some interest in the NHW codec.He has studied several directional wavelet transforms (notably HWD directional transform), and he came to the conclusion that directional transforms will bring marginal improvement, not significant in the case of my compression codec.This also confirms what I have read from

Hello, Just a quick message to correct what I have said in my previous post.It finally seems not that easy to code small wavelet coefficients to have a good precision, and SPIHT is certainly a very good algorithm for that, -and I know there are SPIHT experts that can make very good SPIHT-based codecs-.I have chosen a new and different approach, the multistage residual coding, so I will try to

Hello, I have improved a little the NHW codec.I have improved the dequantization in the wavelet HH band, and little improved the -l2 (and lower) quality setting.I have also added a -l3 lower quality setting (-15Ko, exp), I have increased the quantization for this other setting, and I start to remove higher wavelet coefficients, but this is not optimal... The artifacts start to be noticeable for

Hello, I forgot in my last reply that my DWT implementation can be speed up, for example I'm doing for now: for (;_X1<_E_;_X1++,_RES+=2) //dilatation { _RES[0]=_X1[0]<<3; _RES[1]=(_X1[1]+_X1[0])<<2; } then for (;_X2<_E_;_X2++,_RES+=2) //details { _RES[0]-=(_X2[1]+_X2[0])<<1; _RES[1]+=6*_X2[1]-_X2[2]-_X2[0];

Hello, No advance for now on the NHW codec, I am still working on a new quantization scheme to scale down the compression ratios but without luck... Any advice, idea is very welcome.I will also have to correctly code the wavelet filerbank and process on rows and columns and suppress the image transposition (this is for long overdue)... will win few cycles... there are other parts to speed up (in

Hello, I have finally added 2 lower quality settings for the NHW codec: -l1 (-5Ko) and -l2 (-10Ko).I use a quantization of 0.935 and 0.88 (kind of quantization), and I decrease residual coding on the first order wavelet image. I have updated the demo page: http://nhwcodec.blogspot.com/ . These 2 lower quality settings are still experimental.If you could find time, would be interested in any

Hello, Just a very quick message to let you know that I have added a higher quality setting (-h2, +10Ko) and I have added now residual coding on the 512x256 wavelet image for the higher settings.Precision is a little better.-I also still apply the post-processing function on the 512x256 wavelet image for now.- Here is the link for the binaries (as I can not link them in my blog for now):

Hello, I have improved quality for -l1->-l4 settings.I have properly set up the wavelet coeff threshold of the dead-zone according to the different wavelet subbands, I have then saved another 1Ko per .nhw files without noticeable difference and so I have raised again the quantization.The reconstructed images have now a better precision and still a good neatness. Update at:

Hello, I have just tested new next lower quality settings (-l3 and -l4), I can diminish residual coding but if I increase wavelet coeffs threshold there is more aliasing.And even in the current mid quality settings there is some aliasing, this is the big drawback of the NHW codec. SPIHT algorithm is good for that as for example Rududu codec doesn't have aliasing at all at mid compression and

Hello, I would like to discuss a little about the NHW codec and its state after nearly 5 years on the Xiph forums. I also know that if I would like to discuss I'd better go to the great Doom9 and Encode.ru forums but for now I find that my codec is too experimental for these professional forums: - the codec is only for fixed 512x512 size, just a test tool. - there is only mid compression -

Hello, Just a quick message, I have improved the -l3 lower quality setting.I have increased the quantization to 0.8 and decrease a little the denoising, and so to save 1Ko in average, I have added a 8x8 block variance analysis.Blocks that have a low variance are averaged to save bits.The -l3 lower quality setting is a little better now. For the -h3 higher quality setting, yes for now I do not

Hello, I have re-tested -l4 high compression setting and it's clear that it lacks of precision on degraded, rather blurred images. So I don't know if it is a good idea to base the other lower quality settings (-l5,-l6,...) on -l4 setting.I have tested the NHW codec against x265, x264, Daala, WebP, Rududu, DLI and it's clear that at high compression these very good codecs have more

I don't mind at all. I imagine there are more people like me out there who have been following your work, but haven't said anything. I agree that a series of pages explaining how things work may lead to more contributions. At the very least it would lead to more people being better educated on how wavelets work in image compression. But, this is your project, if you don't have the

Hello, I was testing quickly some other lower quality settings -l3, -l4 because high compression is what really lacks to the NHW codec. In fact I can remove -5Ko of residual coding on Y,U,V comps for -l3 and I can remove -10Ko always of residual coding for -l4, and -l3, -l4 settings will be really better than the current ones implemented. I can also increase the wavelet coefficients threshold

Hello, These last 2 months I have been in contact with a very impressive and friendly engineer from Intel who has written an article on my codec and the 4-5 new codecs in general that competes with HEVC.He finally answered me that as Intel is a founding member of the Alliance for Open Media and chairs several MPEG WG around HEVC, they won't be able to put extra resources on the NHW Project.So

Hello, I've found some time to get back to the NHW Project.In fact a Xiph forum member told me that even if I will start a new job, he hopes that I will still continue to develop a little the NHW Project, on my spare time.I told him that I would furthermore spend my spare time on the NHW Project if a community around the project could emerge... and he told me that certainly the best way for