Area around line blurring on movement?
 

For some reason the area around the referee blurs when he moves off the half court line. Then when the camera pans left, the discoloration either side of the half court line disappears.

What's going on here?

Cheap camera + bad exposure + bad lighting + old tape. Welcome to VHS.

You can use your Premiere Pro to massage discrete areas of each frame individually. But I wouldn't think it's worth it.

How does poor lighting cause that effect?

Look at how that bright circle affects the comntours and details inside it. That circle was too bright for the camera's sensor to handle properly. The effects are caused by probloems you've heard described earlier: clipping, blooming, and ghosting.

I've heard of ghosting, but I don't recall any explanations of it?

I've been over this, I've done most of a restoration pass on it already (this is the one where the lordsmurf script removed the ball), so I'm across the issues with things being blown out and such. It's specifically the odd behaviour around the lines that has me puzzled.

Tjhat bright "glow" just as the guy moves left looks like ghost trail to me. Camera fault.

Could it just be that he's obscuring the line, so that darker area doesn't show up, and it's just the absence of that?

Attached what I've managed to do with this tape thus far.

-- merged --

Had another go at it. Feedback would be appreciated.

Considering the bad lighting, underexposed shadows, some oversaturation, and busted tape, it's a very good cleanup. There is some blurring and a missing limb or two on some corrected frams, but hardly noticeable and IMO unavoidable under the circumstances. Nice work.

I'd make a suggestion about the green color cast and discoloration in the brights. The filtered sample looks better than the earlier one, which is too blue everywhere. I used the original frame 203 to make corrections with Colormill. A .vcf for the ColorMill settings I used is attached. I also used Crop() and AddBorders to center the original image. I didn't address the underexposed shadows, but I don't suppose viewers would miss anything. The ContrastMask() technique might help, but not much with this original.

If you're as concerned about the pure black of the borders that you used to mask off an additional 5% of the image, I note that the borders in your filtered sample aren't black. They're dark Blue (RGB 0-0-9). The green haze is still present in the brights and the court looks a bit pink. Overall, shadows are rather inky and some shadow detail is crushed.

filtered frame 203 from the posted sample:
http://www.digitalfaq.com/forum/atta...1&d=1488468200

Original frame 203 (Crop/AddBorders, ColorMill). RGB 0-0-0 black borders.
http://www.digitalfaq.com/forum/atta...1&d=1488468321

I actually had two players really obviously morph from under the basket to the free-throw line at one point. But the dropout was at the top of the frame, so I just used a matte to restrict the version that had been through lordsmurf's script and ReplaceFrames to just that area of the screen.

I spent a bit of time trying things on those, couldn't fix it without ruining something else. By the looks of it you shifted the hue until the discoloration disappeared, then adjusted from there?

If you mean the first comparison I posted, they were both filtered. I just badly overcorrected the first time.

Is there that much more in there?

I deliberately darkened some of the near-black in the crowd using a luma qualification, just because it looked a bit flat otherwise. Makes the court pop a bit more, and I didn't see any issues that felt like they negated the benefit. I left the very bottom of the range alone. Affects roughly 9% through 14% white.

Odd. I had to re-crop in Premiere after color correcting for exactly that reason, and they're showing up as 0-0-0. They're 16-16-16 in VLC.

TBH the whole thing is kind of a mess because I got the Color Correction Handbook about halfway through. I'm now doing the bare minimum in VDub and saving color work for Premiere, whereas this one is half-VDub, half-premiere, and a general pain to go back and alter. Should probably just start over.

I also saw you post something in another thread about correcting colors based on the idea that greyscale elements should have equal RGB values, so it was mostly just going through with a color picker in the lights, mids, and darks, and doing an RGB correction that way. Which obviously does nothing for the discoloration.

I have no idea how the first version ended up so freaking blue.

-- merged --

I gave it a whirl using HSL controls in Premiere, and it doesn't work. Surely they'd function the same as the ones in color mill?

-- merged --

That thread's a bit of a mess, with various versions of at least three different filters, some of which seem to have compatibility issues with various things. Most of it appears to be about HighlightLimiter().

So if I create a ContrastMask.avsi file in my plugins folder with this text, will that work?:
I'm not able to try it out at this moment.

Same with HighlightLimiter. Not sure which is the latest version of that, or if any of them even work anymore.

I know you said it probably wouldn't help much, but any technique I can add to my repertoire would be good.

Yes, ContrastMask went through a handful of versions in that doom9 thread. The one you posted is the debugged .avs. As for HighlightLimiter I never had much use for it and found it worked only for some very special cases, if at all. The annoyance with ContrastMask is that the default value for "enhance" is 10.0, which is pretty strong and creeps up into the midtones with often foggy results that have to be tweaked with something like ColorMill or grad curves. If darks are badly crushed in-camera, nothing much will help -- a lot of noise "down there" in those cases.

You'll find that lower values for "enhance", around 2.5 or less than 4.0, work best in most cases. Set it using sometyhing similar to this: ContrastMask(enhance=2.5). I tried it with your original frames. Didn't get much in return, but you can try it.

The "gaussianblur" line in the .avs plugin requires the VariableBlur plugin, attached.

I gave one of the HighlightLimiter versions a whirl, just to see what it did, and it actually made the keyways look a bit less washed-out. Not sure if that's better or worse or simply going to be canceled out by a saturation drop later, though. Rendering out just to see how it goes.

My primary thought with that one was actually another file I have with a huge gap between near-white and white. Not sure if that's what it's supposed to help with, though.

Ran ContrastMask at defaults and it just seemed to wash out the shadows. Tried 3, it seemed to be better, although it still bumps the blacks up.

This is another reason I darkened the crowd and back wall a bit; hides the noise that remained after running it through AviSynth. You can actually hear one of the guys behind the camera complaining about how awful the lighting is (worse than usual, apparently), and the other guy shrugging it off as 'there's nothing they can do about it'.

Can't be too harsh, though: the guys on the camera are just squad members who didn't make the playing roster that week.

As you noted, plugins like ContrastMask and HighlightLimiter are two more tools in the toolbox. Sometimes they save the day, sometimes not so much. I found both to be handy in some situations, along with tweaking using things like curves and other tweakers.

If I want to look at just the Y channel, will Greyscale() do that? I'm familiar with UtoY() and VtoY(), but there doesn't seem to be any clearly-noted Y equivalent.

I don't even notice a line blur, just really rotten color. And it can't be fixed. Most likely, the gym had multiple temperature lights. I see too much of that in school gyms.

The line itself doesn't blur, but there's this weird blurry patch that appears behind the referee as he moves off the half court line.

Color-wise, sanlyn's seems pretty good. I've got similar using ColorMill's hue before taking it to Premiere for the rest of the color work. Still not sure why changing the hue in Premiere doesn't eliminate the cast in the brights.

It's the same venue as the 'flickering colors' game.

As long as the source being fed into Greyscale() is YCbCr, yes. I asked the same question on Doom9 years ago.

Reiterating this because with another tape, I was getting very poor results with Premiere and tried ColorMill's hue...and it worked. So what's the difference between them?

Same venue, similar issues, and I was getting the floor decent but sky blue jerseys were turning an awful green color in Premiere. So I used a secondary correction to shift them back, and it looked okay but the floor didn't quite seem right. Tried ColorMill and I could swing the floor and yellow/gold jerseys around to the same point without sacrificing the blue.