[theora] NHW Project - lower quality settings

Sun Mar 11 20:58:37 UTC 2018

Hi David,

Many thanks again for your answer!

Yes a proper website and demo pages are very needed, not to say mandatory
to attract attention and contribution.But I don't have the skill and
software to do graphical design, and as I want to do professional looking
website and demo pages, I have then to put it on pause and search for a
solution...

I am also currently very involved in quality improvement and high
compression, it takes a lot of time, so I am focusing on it for now.

Yes the NHW Project is a labor of love for more than 11 years now, and I
had to have a lot of motivation all these past years because the industry
was really not interested in the NHW Project... Let's hope that with the
recent quality improvements, it will change, it will start to interest some
people and maybe we'll find a niche for the NHW Project, would be so
great... but very not sure...

Many thanks again for your support, it is much appreciated!

Cheers,
Raphael

2018-03-10 17:38 GMT+01:00 David Willmore <davidwillmore at gmail.com>:

> 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 time or interest, don't
> feel compelled to do it.  Clearly, NHW is a labor of love for you and
> I wouldn't want that to change!
>
> On Sat, Mar 10, 2018 at 11:22 AM, Raphael Canut <nhwcodec at gmail.com>
> wrote:
> > 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 it will be more easy then to contribute for
> > people who want and have time.
> >
> > For now, I focus on high compression settings, for me it's very complex,
> but
> > currently high compression settings are mandatory for a new image/video
> > codec.
> >
> > Many thanks again for your feedback!
> > Cheers,
> > Raphael
> >
> >
> > 2018-03-10 16:57 GMT+01:00 David Willmore <davidwillmore at gmail.com>:
> >>
> >> I enjoy reading your posts and always find them educational.  I don't
> >> have anything to contribute other than my appreciation.  Thank you!
> >>
> >> On Fri, Mar 9, 2018 at 1:03 PM, Raphael Canut <nhwcodec at gmail.com>
> wrote:
> >> > 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
> >> > precision.But they also tend to blur/decrease neatness-sharpness of
> >> > image
> >> > where the NHW codec would enhance image neatness/sharpness.But that's
> >> > right
> >> > that on degraded, blurred images where there is no neatness to
> enhance,
> >> > the
> >> > results start to be not good and lack of precision.So for now, I
> >> > recommend
> >> > to use -l4 setting on well-defined, good quality images.
> >> >
> >> > I have also "simply" increased the wavelet coeff threshold of the
> >> > dead-zone
> >> > for -l5 setting (to save -5Ko), but the quality drop is too big for
> >> > now.The
> >> > other codecs (above) don't have that drop in quality from -l4 to -l5
> >> > compression.So apparently, there needs to be more smartness to pass
> from
> >> > -l4
> >> > to -l5 with the NHW codec.I'll try to work on this, but it's extremely
> >> > complex, for me...For example, Rududu doesn't have this problem, the
> >> > codec
> >> > source code has been made available recently on GitHub, I have started
> >> > to
> >> > study it and it is very powerful: advanced SPIHT tree-like coding,
> >> > advanced
> >> > variance-based context modeling, advanced range coding, and other
> >> > things...
> >> >
> >> > So to sum up, all the very good codecs quoted above have a very good
> >> > precision at high compression but they tend to decrease
> >> > neatness/sharpness,
> >> > on the contrary of the NHW codec, but on degraded images where there
> is
> >> > no
> >> > neatness/sharpness, the NHW codec then lacks of precision...
> >> >
> >> > Last but not least, for now the big advantage of the NHW codec I see,
> is
> >> > that it is very fast.The NHW codec is way faster than the codecs
> above,
> >> > for
> >> > example it is still now H.264 technology that is used in mobile
> devices,
> >> > and
> >> > the NHW codec compared to ultra-optimized x264 is x3 times faster to
> >> > encode
> >> > and x1.2 times faster to decode, that is to say that with good
> >> > optimization
> >> > (SIMD, multithreading) the NHW codec will be x12 times faster to
> encode
> >> > and
> >> > x5 times faster to decode than x264...
> >> >
> >> > Again working on high compression is very complex, and any help would
> be
> >> > very welcome.And I know there are experts out there, more skilled than
> >> > me,
> >> > that could have very good ideas for the NHW Project, if they could
> find
> >> > the
> >> > time...
> >> >
> >> > Do not hesitate to contact me!
> >> >
> >> > Many thanks!
> >> > Cheers,
> >> > Raphael
> >> >
> >> >
> >> >
> >> > _______________________________________________
> >> > theora mailing list
> >> > theora at xiph.org
> >> > http://lists.xiph.org/mailman/listinfo/theora
> >> >
> >
> >
>
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