Selur's Little Message Board
Horizontal Banding / overshoot tips ! - Printable Version

+- Selur's Little Message Board (https://forum.selur.net)
+-- Forum: Hybrid - Support (https://forum.selur.net/forum-1.html)
+--- Forum: Problems & Questions (https://forum.selur.net/forum-3.html)
+--- Thread: Horizontal Banding / overshoot tips ! (/thread-3508.html)

Pages: 1 2

Horizontal Banding / overshoot tips ! - ToiletDuck - 19.12.2023

Hello,

I like to know what can be done (filter or other) to counteract horizontal banding / overshoot in video captures ?
This happends most often in dark scenes..

First thing that comes to mind is DGdenoise, but i don't want to loose to much detail / crispnes = sharpening !!
It seems to work, but the image lost some detail and is like flatten / washed out ..

See this pictare to have an idea what iam talking about.. 
you might want to zoom in to see it more clear .. !
[Image: horizontal-banding.png]

EDIT:

Seems, Minideen did the trick and got rid of the banding without losing any detail to pictar xD ^^
Have to test it on other media files though..

Before minideen  Sad
[Image: before-minideen.png]

After minideen  Big Grin

[Image: after-minideen.png]

RE: Horizontal Banding / overshoot tips ! - Selur - 19.12.2023

Doesn't look like banding. For banding using de-banding filters would be the way to go.
Filtering that I would recommend using a denoise or strong deblocking filter with a luma mask.

Cu Selur

Ps.: Would need a sample to recommend something explicit, if you want to filter an image use an image editor.

RE: Horizontal Banding / overshoot tips ! - ToiletDuck - 19.12.2023

(19.12.2023, 17:18)Selur Wrote: Doesn't look like banding. For banding using de-banding filters would be the way to go.
Filtering that I would recommend using a denoise or strong deblocking filter with a luma mask.

Cu Selur

Ps.: Would need a sample to recommend something explicit, if you want to filter an image use an image editor.

You do see the horizontal strait bright area's flickering up do you?  I especially posted an thumbnail wich you can use to zoom/magnify the image to see it more clearly ..
Therefor i call it banding for lack of better words.

essentially it's caused by using sharpening filter → overshoot most defenitely ..  
That specific sharpening filter i use lacks overshoot controll you see..

But it's the best filter in terms of exposing details in the picture compared to others imo..
so far, it looks very good combined with minideen... ^^ The overshoot is much less to none now..

Also, bad compression (Low bitrate + Fast encoding) can cause the same phenomenon fyi...
The compresion artifact magnifies the use of certain filters..

cheers,
Td

RE: Horizontal Banding / overshoot tips ! - Selur - 19.12.2023

Looks like compression artifacts.
I agree those probably happened due to over-sharpening which causes ringing and then a too low bitrate.
=> Denoiser and/or Deblocker masked with a luma mask to only filter dark areas seems like the way to go, but if minideen does the job for you thats fine.

Cu Selur

RE: Horizontal Banding / overshoot tips ! - ToiletDuck - 19.12.2023

(19.12.2023, 17:59)Selur Wrote: Looks like compression artifacts.
I agree those probably happened due to over-sharpening which causes ringing and then a too low bitrate.
=> Denoiser and/or Deblocker masked with a luma mask to only filter dark areas seems like the way to go, but if minideen does the job for you thats fine.

Cu Selur

Plus+ the fact that iam doing an encode at 1080p → No T & B black borders = fullscreen image = more pixels / bits envolved compared to SD standard resolutions  Dodgy

so yes, it's finding the right balance between compression and quality atm ..

Iam often experimenting with eposide discs, to get One season to fit only 1 BD25 maintaining close to original quality or even better ^^
then i create my own custom bluray disc and title menu's..

cheers,
TD

RE: Horizontal Banding / overshoot tips ! - Selur - 19.12.2023

That's up to you to decide what is enough or too much.
I just suggested what I would try. Smile
=> happy hunting

Cu Selur

RE: Horizontal Banding / overshoot tips ! - ToiletDuck - 19.12.2023

(19.12.2023, 18:27)Selur Wrote: That's up to you to decide what is enough or too much.
I just suggested what I would try. Smile
=> happy hunting

Cu Selur

I have tried artifact Deblocker before.. But honestly, it masks artifacts by blurring the image too much imo .  ← There lies the strenght of Deblocker, no matter what settings.. Not to mention its very gpu/cpu taxing too that filter IMO !!

Essentially x264 is able to use deblock algorythm anyway ... (-nr line comes to mind)

And my goal is to enhance image as much as possible but using the lowest bitrate possible to fit a BD25 structure you see..

So you, i want atleast to keep / maintain the same CQ or improve it..  Big Grin

RE: Horizontal Banding / overshoot tips ! - Selur - 19.12.2023

Doesn't sound like you tried (like I suggested) using a mask to limit what gets filtered. Angel

Cu Selur

RE: Horizontal Banding / overshoot tips ! - ToiletDuck - 19.12.2023

(19.12.2023, 18:40)Selur Wrote: Doesn't sound like you tried (like I suggested) using a mask to limit what gets filtered.  Angel

Cu Selur

 i get what you trying to suggest.. But a deblocker is by definition a mean to blurry edge/block boundaries is it not ?  And i just want the opposite.. sharper+detailed.


But i want to give it a try, wich deblocker would you suggest, and at wich settings?
Have tested many filters under artifacts tab... despot, killerspot etc... but the after image just doesn't look right anymore..

Iam talking about the 3 compression deblockers you can choose from under Deblocker filter section.. fyi

cheers,

RE: Horizontal Banding / overshoot tips ! - Selur - 19.12.2023

Like I wrote: "Would need a sample to recommend something explicit..." + "That's up to you to decide what is enough or too much."
Tongue