similar to: NHW codec

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

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'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, 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,...

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, 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, 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, If it could be of interest, here are new speed measurement for -l13 very high compression setting. For x265 (HEVC), I use BPG codec, and this time I use -m 0 setting which uses the fastest encoding setting of x265.I run the .exe 10x times and I pick the best scores. So here are the timings at -l13 very high compression: Encode time: x265 (BPG -m 0): 80ms NHW: 20ms Decode time: x265

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, 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, Just a quick message to let you know that I have really improved very high compression of the NHW Project from -l8 to -l13 quality settings, and we can still save 2.5KB per .nhw compressed file. Actually I am new to very high compression, it is just 3 months that I am working on it (I put on pause the NHW Project from August 2013 to February 2018 )... And I realize that very high

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 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, Just a quick message to let you know that I have made good quality improvements for very high and extreme compression of the NHW Project (-l8 to -l15 quality settings).The NHW Project starts to be really competitive with x265 (HEVC) at these very high compression ratios.I even find the NHW Project visually better than x265 (HEVC) for mid and high compression! I have also improved encoding

Hello, I would like to thank very much the Theora channel community for their support and help!!! And even recently a Theora channel member proposed me to freely host on his server the NHW Project website, to present the codec on the embedded processors, MCU forums that he knows well, another member forked my GitHub repository!!! Really thank you very much!!! It makes me think that maybe the NHW

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 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 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 Ken, Many thanks for your reply! Yes, I very need to adapt the NHW codec to any image size.But actually it is the least interesting part, I don't think that it is that difficult (compared to creating high compression settings) but it is very boring, annoying... Really not the part that I prefer... For now, as I am jobless, my aim is to have "pleasure" with the NHW Project and