Displaying 20 results from an estimated 3000 matches similar to: "NHW codec - precision"
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
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
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
2013 Aug 28
0
NHW Image codec - Compression Performance
Hello,
Definitely not any (constructive) comments on the NHW Image codec?
According to my tests, it can compare good with reference codecs like
x264 intra and WebP.
Yes, the codec is still experimental and is optimized for visual
(subjective) evaluation, not PSNR.Its main feature is again that it would
have a little more neatness/sharpness and a little less precision (residual
coding is applied
2017 Dec 11
0
NHW Project - lower quality settings - high compression
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
2016 Oct 01
0
NHW codec
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
-
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
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
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
2016 Aug 16
0
NHW codec
Hello,
I don't have advanced on the NHW codec, but now, as a lot of people, I am
following the AOMedia AV1 codec.Just a (late) update of my previous post,
there won't be problem in AOM AV1 with the CABAC scheme, as the codec will
use Daala's multi-symbol entropy coder and/or ANS.That's great! I have even
read on the wiki page, that AV1 will use Daala's PVQ as quantization
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
2017 May 02
0
NHW Project and wavelet codecs
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
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
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
2017 Feb 16
0
NHW Project - 2017 timetable
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
2017 Nov 30
0
Fwd: NHW Project - speed comparison with x265
---------- Forwarded message ----------
From: Raphael Canut <nhwcodec at gmail.com>
Date: 2017-11-30 14:22 GMT+01:00
Subject: Re: [theora] NHW Project - speed comparison with x265
To: fboehm <fboehm at aon.at>
Hi Franz,
Many thanks for your answer!!!
> I appreciate your enthusiastic work on such a complex project like
writing a video codec
Yes, for now the NHW codec is more an
2017 Mar 07
0
NHW Codec - some progress
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
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
2012 Jul 25
4
NHW Image codec - improvement of precision
Hi again,
I have improved precision of my codec (on the encoder and decoder).I have
also improved the -h1 quality setting.-Source code and binaries at
http://nhwcodec.blogspot.com/-.
I am still trying to improve precision of my codec, with keeping my
low-complexity (fast) approach.
I do not totally use the reference (and impressive) block prediction with
different modes + residual coding scheme,
2017 Sep 04
0
NHW Project - fast discrete wavelet transform
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];