AVISynth script needed... low level lighting.

[joshbm]

Hey everyone,

Well I was doing a project and some deinterlacing. The video looks great, no interlacing bands or any signs of deinterlacing. The only problem is now I need to concentrate on the picture.

The picture is horrible, because I filmed it at around midnight-3 a.m. The problem being we had low-level lighting and it gave us this:

http://www.videocdpro.com/josh/lowlight.jpg

It looks kind of bad lol. Anyway I can fix it?

Thanks!
- joshbm

[Mug Funky]

that amount of noise probably can't be fixed without blending too much motion.

it'll look like Johnny Cage's "shadow kick"

[edit]

the problem is really that most noise reduction techniques won't increase the signal-to-noise ratio at all, they will simply blur anything detected to be noise, either spatially or over time. in contrast, human eyes (ears too) can find detail under the "noise floor", so if the noise is too high and noise reduction is applied, the results will be worse than what you started with.

a temporal smooth might look okay on this clip if there's not much motion at all, but you'll need a wide radius, and probably some spatial blurring as well to hide the grain.

[WyldeF1r3]

well, you could experiment with raising the brightness slightly by using tweak, but as mug says, it's going to be difficult to whipe out the noise. you might try fooling around with deen on low settings though the results of brightening and cleaning will probably only be marginal at best

[joshbm]

I've yielded excellent results with MSU Denoiser with a temporal threshold of 50 and a spatial threshold of 40.0.

If you would like I can post my results...

Regards,
- joshbm

[CraigBjorn]

Well, I didn't really do a whole lot of denoising, but as far as picture goes I got it too look like the attachment. Just adjusted the contrast and then did a color adjustment. I did it in the gimp, but if you like it, I could possibly help transfer to avisynth.

http://dougk-ff7.net/~schwa/room.jpg

[CraigBjorn]

My site is back up, and I've loaded the color corrected pic.

[joshbm]

Nice job! I like it! The only thing is I do want to keep the original colors because this scene takes place at night. If I needed to color correct it and make true colors from a night shot to make it look like day-- That would be nice!

[Mug Funky]

a good tip for night shoots is to use a blue filter on the camera (or white balance the viddy cam to something more orange than your lighting).

a blue tint means you can get a way with using way more light, and psychologically it'll still look dark. after all, 8 bits isn't much dynamic range, so the more tricks you can use the better.

also, a higher lighting ratio will make it look darker. so maybe a blue light shining in an open curtain for next time? (yes, it's cliche, but it means you can play with shadows on stuff... always a bit of fun).