[theora] NHW Project development

Thu Dec 2 21:53:44 UTC 2021

Raphael,

Some 15 years ago I implemented limited functionality Theora in our cameras FPGA (it took me 6 month of hard labor), and then gave up - it is a very crowded space and it is difficult to compete with more advanced codecs. And for our other work we anyway need almost raw image data, so we are using JPEG-based JP4 format (https://community.elphel.com/jp4) that we originally developed for Google Books to compress raw Bayer mosaic images. Last few years we work with the thermal images that need 16 bit, so far uncompressed TIFF files. We need lossless 2:1 compression (current recording bandwidth is about half of the image data rate (4 channels of 640x512x60fps, 16 bits), but it will be something simple (prediction by 4 neighbors), and no video. Nature of the thermal images is different from that of the conventional RGB - there is no scaling with exposure and environmental temperature causes shift of the pixel values, not scaling.

We did not post the latest results yet, the last blog is here - https://blog.elphel.com/2021/07/calibration-of-the-lwir16-camera-prototype/

Andrey

---- On Thu, 02 Dec 2021 14:34:25 -0700 Raphael Canut <nhwcodec at gmail.com> wrote ----

Hi Andrey,

Thank you for your answer.Actually, NHW is very low-power so I think it could be geared toward any hardware.But actually I don't have hardware skills, so NHW is not a real hardware project for now maybe? I agree with you that it is extremely difficult (for me) to build a community around NHW, I'm certainly very bad/underskilled at it.Any help is welcome!

Cheers,

Raphael

Le jeu. 2 déc. 2021 à 21:13, Andrey Filippov <mailto:andrey at elphel.com> a écrit :

Raphael,

I do not believe it is possible to build a viable community around most hardware projects except super-universal based on very cheap/high-volume products like Pi or Arduino. We see the commercial benefits of Free Software/Open Hardware as it adds value to the hardware as users are ready to pay extra for the Freedom.

Andrey

---- On Thu, 02 Dec 2021 12:59:34 -0700 Raphael Canut <mailto:nhwcodec at gmail.com> wrote ----

Hello,

I know there is no community around NHW, but I would have liked to know 
 what you would like to see improved in the NHW codec.I know its results
  are not perfect for now compared to high-end AV1/VVC codecs for 
example,  but could be ok giving its extremely fast speed.-However on 
high  quality images, I notably like its good results because of its  
neatness.-

Regarding things to improve, there is the problem of aliasing, I have  
started some quick experiments as I mainly find that aliasing appears in
  NHW along "low-contrast edges", but I have also seen some very  
impressive results of directional filters like the ones used in CDEF  
filter in AV1, because they estimate the "strong edge direction" and  
align all the pixels on that "strong edge direction"  which could  
depixelize/remove aliasing.I have also started to implement a banding  
detector (with its main analysis on the 128x128 wavelet DC image) in  
order to remove banding, and it's only the beginning but I have  
promising results.I have also started to improve the entropy coding  
scheme of the wavelet DC part, for now I have a very fast processing  
that gives another 1KB saving on that part in average, but I have an  
error on some few images, I don't think I contradict the compression and
  information theory principles, I think it is more a corner case that I
  did not see for now and so that I don't handle, but it takes a lot of 
 time... I'll also have to better handle the chroma channels and notably
  add chroma from luma technique.

Some people also tell me that the priority now is to adapt NHW to any  
image size, but actually this is the boring task for me currently, and I
  am a little reluctant for now.

All that to let you know that I really like more to work on my codec,  
and so I would like now to work full-time on it again, but there is  
always the big problem of the salary at the end of the month.As the  
industry doesn't show interest in NHW, I would like to ask sponsoring  
for this project on the Internet.But some people told me that I failed  
to create a community around NHW, and with just 27 followers on GitHub  
and 8 followers on Twitter (that's very weak), I can not hope more than 
 10dollars/per month of sponsoring/donation.

Do you think this solution/sponsoring is possible? Or on the contrary,  
NHW will be just a spare time hobby, because there is nothing more to  
expect out of it?

Any help/opinion is very welcome!

Cheers,

Raphael 

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