Optimized Image Compression (DCTune) technology

[Dali Lama]

I was searching the net for information about custom quantization matrices and found this site. It speaks of a NASA developed software program that optimizes the quantization matrix per frame. That's awesome, we need that for Xvid.

http://technology.arc.nasa.gov/techopps/dctunenew.html

Exciting Stuff,

Dali

edit: http://www.google.com/url?sa=U&start=2&q=http://vision.arc.nasa.gov/projects/dctuneproto.pdf&e=912

This describes what DCTune does and it says that its available for trial!!! Must find it.

and

http://www.google.com/url?sa=U&start=3&q=http://vision.arc.nasa.gov/publications/sid93/sid93.pdf&e=912

Provide a description of the way to do Optimized Matrices. It also talks about Luminance Masking.

A genius needs to code this into Xvid :sly:

[Rrrough]

Nice find !!!
from first glance, aren't there a lot of patents involved ??? but definately interesting stuff...

This describes what DCTune does and it says that its available for trial!!! Must find it.

yep : look here :

http://vision.arc.nasa.gov/dctune/

cheers

[Dali Lama]

Rrrough,

Great job.

Looking through the readme, I see that my hope is true. It will output the custom matrix that will provide optimal quality at desired bitrate. Incredible. Now our Xvid encodes can use optimized matrices.

Enough talk, lets make some tests :sly:

Dali

[Rrrough]

couldn't agree any more... or like some genius said somewhere on another thread :

maybe more testing is needed...wait a minute of course more testing is needed

:D :D :D :D :D

btw. please tell me, what build you are using, so I will use the same, which will make our tests more comparable...

[Dali Lama]

Rrrough,

Thanks for the compliment :o I am using Koepi's Build XviD-04092002.

I will begin testing shortly,

Dali

[ReferenceDivx]

Here is a link to a page that has a few good articles on optimizing the dct matrix http://citeseer.nj.nec.com/context/196955/0

we might be able to use the code in jpeg2000 to come up with custom matrices for each frame. Dctune looks interesting. I hope to look at it more in the next few days.

Would it even be possible to use custom matrices for each frame?

[iago]

@Dali Lama

I'm also looking forward to hear about your test results. Good luck! ;)

best regards,
iago

P.S.: I haven't tested the low and ultra-low matrices you posted yet, but I got very good results using the one posted by ReferenceDivx with a two-pass full XviD encode, which is mentioned in detail in the related XviD thread.

[dimzon]

Hi! I created script for automatic custom matrix generation (using DCTune). Check it here:
http://forum.doom9.org/showthread.php?s=&threadid=74463&perpage=20&pagenumber=3#post482070