similar to: NHW Image codec - lower quality settings

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, So here is the compression scheme that I don't know if is covered by patent. I use it on the wavelet DC parts.It outputs 1 byte (8 bits) words.There is 5 modes: - 1(MSB) | 7 bits to store value (0->127 range) - 01 | 6 bits to store val[n+1]-val[n] | val[n]-val[n-1] if each in the range [-4,4] - 001 | 5 bits to store val[n+2]-val[n+1] | val[n+1]-val[n] | val[n]-val[n-1] if each in

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, 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

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, Ok, and that's too many work to review a source code.In my codec, I have 3 compression schemes, I think 2 are not patented, but the third... I don't know.For the rest, I think my codec is patent-free (I don't use SPIHT,EZW,zerotree methods), even the wavelet transform is new and don't use the lifting scheme nor the convolution product. Else, if you found time to review the

Hello, In my last post, I seemed to say that there were no directional wavelet transforms that would give improvement to the NHW codec, but are directional wavelets an active research field today? I have also seen some recent patents on advanced and improved SPIHT, and I am a little surprised that there is no "up-to-date" state-of-the-art wavelet codec.Rududu in April 2008 was the last

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 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

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 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):

Hi David! Many thanks for your very encouraging and kind feedback!!! (Hope you don't mind that I made your post public on the Theora channel). I try to be the more sincere as I can in my posts.Some people suggested me to make demo pages to explain how the codec works step by step, and I realize that it would be good, because certainly it will show that the NHW codec is not that complex and

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, So thanks to helpful forum feedbacks, I know now that I have to create a website for the NHW Project, make demo pages of the technology, and all that with good visual design.It won't be such easy for me... For example, I can easily supply a description, explanation of the different steps of the algorithm, I can supply images encoded at mid-compression with NHW, x265, WebP, JPEG,...

Hello, I spoke a little quickly when I proposed a £1000 rewards... because there is still some "easy" processing to increase compression in the NHW codec, like increasing wavelet coefficients threshold, decreasing again residual coding.I will try to code it tomorrow and this weekend, and will let you know what it gives. A new idea I'm thinking of not to have too much aliasing and

Hello, With -l5 quality setting, I have learned that I can increase wavelet coeff threshold to 12 in the HH band without noticeable difference in the reconstructed images.With this processing, I win in average 1Ko in the compressed .nhw files, and so I can raise the quantization for -l1->-l4 settings (0.935->0.955,0.88->0.9,0.87->0.89) and so these settings are now better, there is a

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, 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 am still progressing with very high compression and I have corrected a processing, so now very high compression (-l10 to -l13 quality settings) has really better precision and so better quality. I have also released a first draft of a new -l14 very high compression quality setting. More at: http://nhwcodec.blogspot.com/ Just a remark, the entropy coding schemes start to be less

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