Displaying 20 results from an estimated 2000 matches similar to: "NHW Project - lower quality settings - high compression"
2018 Mar 09
0
NHW Project - lower quality settings
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
2017 Feb 24
0
NHW Codec - new study on 30 images
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
2013 Jun 19
0
NHW Image codec - lower quality settings
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
2018 Mar 10
0
NHW Project - lower quality settings
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
2018 Mar 10
2
NHW Project - lower quality settings
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
2013 May 29
1
NHW Image codec - 2 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
2013 Jul 03
2
NHW Image codec - higher quality settings
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):
2018 Feb 18
1
NHW Project - high compression -l4 setting
Hello,
For those interested, I have added a -l4 high compression setting to the
NHW codec ( http://nhwcodec.blogspot.com/ ).This setting is very
experimental, I have boosted the sharpness for this one, but it can lack of
precision on low contrast areas.
This setting still maintains a good neatness and when it will be validated,
I will then make a new 0.1.4 version for the NHW Project.
High
2018 Mar 11
0
NHW Project - major quality improvement for -l1->-l4 settings
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
2017 May 27
0
NHW Codec - aliasing
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
2018 May 28
0
NHW Project - high compression & community
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
2018 Mar 17
0
NHW Project - quality improvement - proper subband quantization
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:
2017 May 25
0
NHW Codec - next lower quality settings
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
2018 Aug 19
0
NHW Project - new -l8 "very high compression" setting
Hello,
The -l8 "very high compression" setting I posted was not really good.Now I
have corrected and improved it, and now the -l8 quality setting is really
better, more precision and more neatness.
I think now it is a good setting, and I have started to compare it with
x265 and it can be now competitive.
More at: http://nhwcodec.blogspot.com/
Do not hesitate to test it and give me
2018 Aug 17
2
NHW Project - new -l8 "very high compression" setting
Hello,
For those interested, I have added a -l8 "very high compression" setting to
the NHW Project.
I have added an experimental processing to remove details and preserve
neatness.I have also now a fast estimation of entropy of wavelet
coefficients and I use it accordingly to the image complexity but it is a
very first version... With these new processings, the entropy coding
schemes
2017 Feb 02
0
NHW codec - precision
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
2018 Mar 27
0
NHW Project - quality improvement for -l3, -l4, -l5 settings
Hello,
I have improved quality for -l3,-l4,-l5 settings.I have diminished residual
coding and I have raised again quantization.These settings are now better.
Update at: http://nhwcodec.blogspot.com/
The NHW Project with this version starts to be competitive at high
compression with x265.
Any feedback welcome!
Cheers,
Raphael
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2017 May 12
0
NHW Project - some update & call for members
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
2020 May 13
0
NHW Project - new version
Hello,
I have made a new version of NHW.This one has more neatness and more
precision for -l4 to -l11 quality settings, which are the general-purpose
compression settings.It is actually just one parameter better tuning based
on my visual evaluations (no real new developments... it was 14 months now
that I did not develop the NHW Project...).
Files size is just a little bigger, but we can still
2017 Feb 20
0
NHW Project - some advice
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