Adviced Deblocking settings?

[killerhis]

I've read that BlindPP can handle deblocking. I got this source and I want to deblock it, anyone got some adviced settings for it. Like for hard deblocking/soft deblocking, ect.

Thankz

PS: let try to keep this post clean, so no impossible or weird settings please, thankz!

[Didée]

Okay, let me be the first one to pollute this clean thread ;)

I can't assume what you already figured out and what not, so I'll try to give a compact overview.

First off, you must be sure that the blocks that you want to deblock are aligned at 8-pixel boundaries, speak: no cropping, no resizing before you apply blindPP! If your source is interlaced, set "ipp=true", if it's progressive then the default is already right (ipp=false).

The parameters are:
quant=, cpu2=, moderate_h=, moderate_v=

set "cpu2" to "xxxxoo" for horizontal+vertical deblocking on luma and chroma, to "xooxoo" for horizontal luma + vertical chroma deblocking, etc. You get the idea.

"quant" speciefies the overall *strength* at which the deblocking process is to perform.

moderate_X specifies the horizontal, resp. vertical, sensitivity *where* to perform deblocking, and where not. (Or: the sensitivity for "reckognizing" that a block is present.)

While "cpu2" and "quant" are pretty clear, the "moderate_X" settings are a little like a black box:
originally from this thread (http://forum.doom9.org/showthread.php?s=&threadid=54448&highlight=blindpp):

Didée:
Nic, while we're at blindPP, could you elaborate a little on the mechanics of moderate_h|v? The docs don't explain that very well. We have the defaults of 25|40, 'horizontal' and 'vertical' is obvious, and we know smaller values are more aggressive, bigger values less ... okay.
But honestly, I've no idea in which way these two values actually are used. Is it a threshold (against what?), is it a strenght setting, or sort of a 'distance' value, is it ...

Nic:
Its complicated, ill have to look at the source to remember. Its is a threshold that states whether to use a strong filter or a weaker filter in the code. But I can't remember how that threshold is calculated.

Even if I explain it, I feel it would be a little complex to do anything with the explanation, as working out better thresholds will only come with experimentation. I came up with 20 and 40 while doing lots of testing with the film Ronin.

In the end, no-one can do the testing that you have to perform on your own, killerhis ...

quant=2, moderate_h=35~45, moderate_v=45~55 will give you a very gentle softening on strong, clearly visible blocks only. It will retain very much detail and sharpness, but will also let intact weaker blocks, and not totally kill stronger ones.

quant=16, moderate_h=15~20, moderate_v=20~30 will perform rather strong deblocking on almost anything that perhaps could be a block ;), but will also smooth away a lot of detail and sharpness.

The rest is up to you, your taste, and your source :)

One other example:
Since the excellent denoiser "PixieDust" may sometimes cause blocking by itself in moving areas, I sometimes do

PixieDust(2).BlindPP(quant=8,cpu2="xxxxoo",moderate_h=45,moderate_v=55)

This takes away a good amount of the most visible blocks, IF and only IF PixieDust has produced some. On the remaining 99.8% where PixieDust didn't block, this will do almost nothing, like desired.

Hope this was of any help, and sorry for the pollution ;)

- Didée

[DarkNite]

What is this source? What are you doing before BlindPP? Try to be as clear as possible when asking questions as it saves both yourself and us a lot of time.

Anyways, if I were using BlindPP I would usually use something like:

BlindPP(quant=8,cpu2="ooxxox") - chroma only deblocking and deringing

Increasing the moderate_h, or moderate_v settings is tricky. I would try increments of 5 until it looks good to you. It's pretty easy to overdo it with BlindPP, so be careful and be sure to RTFM.

Edit: Doh! Beat to the punch. :)