similar to: NHW Project - blurred edges

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, 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, 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

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 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, 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 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'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, As I said in my previous post, I would like now to accelerate to NHW Codec development.I started in January 2007, more than 10 years ago, and I would like now to see it finished after all the time I gave to it (especially the 3 first years).For now I can only give 2-3 hours in the week-end to the codec development, and furthermore I don't have all the skills to improve it, notably in

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 that's right HEVC and AOM AV1 are better than the NHW codec, even at mid compression.I only tested my codec with quite neat images, hence the good results, but on more blurred, more compressed images, HEVC and AOM AV1 are definitely better, they are also exceptionnal at high compression. So, yes that's right, the NHW codec has very little chance to penetrate the market, it is

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 need advice concerning (quite) blurred images with the NHW codec, as the results on these images are not good for normal and lower quality settings (because for these settings the residual coding is on the first order (256x256) wavelet image and for quite blurred images there is not enough energy, information in this band), but the results can be good with the higher -h2 and -h3 quality

Hello, I don't have worked on the NHW Project this past week (I also have to work on an other project) but I found time today to make an "extensive" testing of x265 (HEVC) and the NHW codec at high compression (-l7 setting). That's right that x265 is a very good codec! Really impressive.The NHW Project is not as good, it can only compete with x265 (HEVC) on quite high quality

Hello, I am slowly working on the NHW codec. I have re-tested the post-processing function in the NHW decoder that was supposed to remove aliasing but that doesn't work at all, and after several tests I still find this post-processing useful.I find that it gives some good results, rebalances the image (but it is very slight).I know that this kind of post-processing must be taken very

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, Yes, that's right, I had the remark that if I say that the NHW codec would have more neatness/sharpness, this must be also accompanied with objective measure.But the neatness/sharpness measure is quite complex to define, and implement. But at classical visual review step, I would find that the NHW codec would be less blurred (maybe PSNR would like blur?...) with more

Hello, Just a quick message to let you know that I have improved -l6 quality setting. This high compression quality setting is now competitive with x265 (HEVC).Actually I prefer -l6 high compression setting compared to x265 on many images (not blurred)... Update at: http://nhwcodec.blogspot.com/ Else, do some of you could test the NHW Project under Linux? Many thanks! Cheers, Raphael

Hello, Yes, that's right.I still think that it would have more weight if I could claim that Xiph has reviewed the source code and find that the NHW codec is royalty/patent-free (better than me alone claiming this...).Maybe it was in this sense that Ralph Giles answered me? Cheers, Raphael 2015-01-15 18:02 GMT+01:00 Jason Self <jason at bluehome.net>: > Raphael Canut asked: >