How to clean up color bleed?

[drzapp]

I have some homemade tapes that have the time/date stamp in the bottom corner. The text is white, and there is a whitish blur to the right of the letters. I'm not sure what this is supposed to be called, I think of it as "color bleed". See the short sample attached.

[sanlyn]

That smearing to the right isn't bleeding. It's ghosting. You have ghosting on the Christmas tree as well, it just isn't as bright as the date stamp. Even the green leaves have smearing. Likely the player is at fault. What capture hardware are you using?

This is a really noisy, low accutance capture, has dark sharpening edge halos and ragged edges. Your cropped frame isn't mod-8, which will be a problem for some encoders and for several Avisynth filters.

[drzapp]

OK- ghosting- I'm just figuring this out Captured from an AG-1980 passed through an ES15 and DVK-100, then used Virtualdub to denoise, color adjust and crop. I ran into the mod-8 issue just today when trying some new Avisynth filters. As I understand it, the X and Y number after the crop have to be divisible by 8... is that correct? I did this capture before I knew that

Could be the AG-1980 has bad caps, I haven't been able to redo it yet, and don't have enough experience to know what problems that could be causing.

Also, this tape has been recorded over at least twice before.

[sanlyn]

Quote:

Originally Posted by drzapp

OK- ghosting- I'm just figuring this out Captured from an AG-1980 passed through an ES15 and DVK-100, then used Virtualdub to denoise, color adjust and crop. I ran into the mod-8 issue just today when trying some new Avisynth filters. As I understand it, the X and Y number after the crop have to be divisible by 8... is that correct? I did this capture before I knew that

Wait a sec. You mean the sample avi that you posted was not a cut of the original capture, but was reprocessed? So, are you asking what's wrong with your capture, or are you asking what's wrong with your processing? Temporal denoisers used incorrectly will produce smeared chroma and ghosting.

The idea behind a lossless capture is not to get a cropped image but to get an unaltered master copy of the original source (Why are you cropping to a nonstandard frame size and screwing up the original aspect ratio properties, and what will you do with it?).

Quote:

Originally Posted by drzapp

Could be the AG-1980 has bad caps

That's possible. I've had my own AG-1980 recapped twice. But from what you say, you didn't show us your capture. You showed us your processing of a capture.

Do other tapes show the same smear or ghost problem?

Quote:

Originally Posted by drzapp

Also, this tape has been recorded over at least twice before.

That would make for a noisy tape, but it wouldn't change the ghosting.

[drzapp]

Ok, here is the capture file (without processing) that I should have posted in the first place. Looks about the same as the processed one, so probably the AG-1980 needs service?

Quote:

The idea behind a lossless capture is not to get a cropped image but to get an unaltered master copy of the original source (Why are you cropping to a nonstandard frame size and screwing up the original aspect ratio properties, and what will you do with it?).

I was following this tutorial for getting rid of the noise on the edges and overscan http://www.digitalfaq.com/forum/newr...#ixzz5d6iHvaYX

Cropping is probably the wrong term- is this considered masking? (Trying to learn the jargon here..)
I just adjusted in the mask as far as I thought it looked good and didn't pay attention to the resulting frame size. Won't make that mistake again.

Some tapes have ghosting, others don't, and I haven't found a pattern to it.

[sanlyn]

Thanks for then lossless sample!

Quote:

Originally Posted by drzapp

Ok, here is the capture file (without processing) that I should have posted in the first place. Looks about the same as the processed one, so probably the AG-1980 needs service?

Well.....give us a little more info on where it was purchased. If it was eBay or similar source, it would definitely need work. However, that one tape and sample doesn't look very much like AG-1980 playback. Not only is the color, noise, and overall brilliance really poor, but it has so much temporal distortion it looks like a poorly dubbed tape. No amount of filtering in VirtualDub would clean it effectively, and stronger filters in Avisynth would make it look even worse. I would caution, however, that AG-1980 service -- while it's definitely worth it when properly done -- is no simple proposition and is expensive. This forum's recommendation for some time has been T.Grant's website: https://www.tgrantphoto.com/sales/in...-test-our-vcrs. A "local shop" would have absolutely no idea what to do with an AG-1980.

I'd suggest you try testing a better tape, preferably a retail tape or at least a tape in better condition, to check differences in performance. Even with a bad or damaged tape, an AG-1980 ought to look better than that sample. I would also try connecting the AG-1980 directly to the capture device and disconnecting the external tbc or proc amp or anything else you have between the player and the capture card, in order to eliminate any other variables in your test.

Quote:

Originally Posted by drzapp

I was following this tutorial for getting rid of the noise on the edges and overscan http://www.digitalfaq.com/forum/newr...#ixzz5d6iHvaYX

That link doesn't do anything. It links to a reply window, not a forum post. Did you mean http://www.digitalfaq.com/forum/vide...erly-crop.html ?. The idea behind cropping is to replace the old dirty borders with new ones and restore the original frame size.

I note that your capture had 6 pixels of solid masking along the bottom border. There are actually 8 pixels of noise down there. Doing that during capture is a waste of effort because you'll just have to clean it up again later. The black mask did reveal, however, that the remaining SMPTE side borders were dark gray rather than black and were very noisy. That's a severely ragged looking video with what looks like poor tracking -- either that, or the original recording machine or camera was having a very hard time. You also have elevated black levels and illegal bright levels that exceed y=235. Levels should be adjusted during capture using VirtualDub's controls and histogram.

Quote:

Originally Posted by drzapp

Cropping is probably the wrong term- is this considered masking? (Trying to learn the jargon here..)
I just adjusted in the mask as far as I thought it looked good and didn't pay attention to the resulting frame size. Won't make that mistake again.

There is no mask on your first sample.

Cropping means removing pixels. If you leave the border pixels as they are and just cover them with black or some other color, that's masking. In Avisynth you remove unwanted border pixels (Crop) and then fill the removed area with new border pixels (AddBorders). No masking is involved. VirtualDub does the same thing, but uses different filters and different terms. Cheap editors and people who don't know better use masking. In any event, the final frame dimensions don't change.

Quote:

Originally Posted by drzapp

Some tapes have ghosting, others don't, and I haven't found a pattern to it.

If the smearing is inconsistent from tape to tape, the only conclusions are: (1) Some tapes are damaged in such a way that a poorly aligned player has problems with it while other tapes play more normally, or (2) the problem is in the tapes, not the player.

There are many reasons why advanced users soon learn the value of owning more than one tape player, even if one of them is less advanced than the other but still decent. Being able to test and compare is one valuable advantage.

[drzapp]

Quote:

I'd suggest you try testing a better tape, preferably a retail tape or at least a tape in better condition, to check differences in performance. Even with a bad or damaged tape, an AG-1980 ought to look better than that sample. I would also try connecting the AG-1980 directly to the capture device and disconnecting the external tbc or proc amp or anything else you have between the player and the capture card, in order to eliminate any other variables in your test.

Took a while, but I got the same clip with the 1980 alone, 1980+es15, 1980+es15+dvk, no color processing and 1980+es15+dvk with color processing. I only have a few commercial VHS tapes, and none of them are cartoon / animation... so maybe not the best video clip for analysis, but maybe it will still be useful?

Quote:

That link doesn't do anything. It links to a reply window, not a forum post. Did you mean http://www.digitalfaq.com/forum/vide...erly-crop.html ?. The idea behind cropping is to replace the old dirty borders with new ones and restore the original frame size.

Yes, that is the post I was trying to link.

[sanlyn]

Thanks for taking the trouble to make the samples. I had to install Magic YUV onm my full-timke machine, as Magic optimized for HD and isn't very efficient for typical standard def work. Your "AG-1980 only .avi" in YUY2 Magic was 73mb size, but as Lagarith YUY2 it went down to 62mb. In thought you might want to consider that if space becomes an issue.

All of the samples had a fairly mild, typical amount of chroma bleed, none more than usual with VHS. The effect will differ with different tapes, with home-camera videos usually being the worst. But bleeding increased visibly with the DVK, and some fine detail disappeared.

The images below also show the effect on overall levels with different components added. As usual tghe ES15 pumped black black levels and contrast a little, and slightly smoothed the image. You might want to double-check to be certain that the ES15's playback noise reduction is turned off. Adding the DVK gave a big jump in black levels and raised gamma quite a bit, to the point where brights were on the verge of clipping and the entire image looked washed out. The proc amp had no appreciable effect.






I don't understand why the ES15 should be required if your playback source is the AG-1980, since the AG-1980 has a very capable line-level tbc. but I realize that you might have included it as part of a test.

[drzapp]

Thanks for the help- I have the es15/DVK combo at the recommendation of LordSmurf. In fact, I bought the DVK from him. For the color processing, I had everything at the middle, so maybe I should drop the brightness and increase saturation if I use it at all?. I have used it to make some really dark videos watchable, so at least it was good for that.

I looked through the es15 menus.. I can't find anything about noise reduction in any of them?

I've been using Magic mostly because it plays well with Vegas and DVD Architect that I use for editing and authoring. I'll try Lagarith again and see if I can get it working. I have a 8TB RAID0 for capture and editing, but it's still getting full! (I know- tempting fate- but it's blazing fast... don't worry, I have it backing up to my NAS every night)

[sanlyn]

Don't apply additional noise reduction filters during capture. You can try correcting color with the BVOP4 during capture, but you'll be sorry with the results and YUV corrections are extremely limited. During capture adjust signal levels so that they stay within the y=-16-235 safe video range, using VDub's capture histogram to check the results. Remember that black borders and head-switching noise will affect the histogram. I see you already applied a bottom border mask and left the image off-center vertically.

If what you want to do is apply slow noise reduction filters, mask borders, and correct color, and think you'll have a perfect capture with nothing left to do afterward, it won't work. On color work alone, VHS changes color balance every few minutes, often every few seconds. How would you monitor the saturation signal levels of your corrections (YUV chroma has to be within y=16-140 values)? It will also affect your ability to clean up chroma bleeding later. If you expect a finished capture right out of the capture card you don't really need lossless capture, so you might just as well use a DVD recorder and be done with it. The idea behind lossless is post-process tweaking and repair, which is far more sophisticated and less damaging than anything you could apply during capture. Remember that whatever changes you apply during capture are permanent, unless you want to do a lot of work undoing something you might change your mind about later.

[drzapp]

Yeah, I had put a 6 line crop in Amarec a while ago and forgot it was still on. I use that because VirtualDub drops frames and loses audio sync, and I like it's interface better.
So it sounds like I don't actually need the es15/DVK, since they are just introducing more problems?
I'm not purposely trying to do all the processing during the capture- I just was following suggestions I've seen about using the es15/DVK for an added TBC. I agree that the capture should be as close to the original as possible, and then clean it up in post.

[sanlyn]

You should be able to use the AG-19080's line tbc by itself most of the time without help from the Panasonic's extra line tbc pass-thru. Remember that the ES15 aklso has frame-level circuitry as well alt6hough it's not powerful enough to overcome a copy protection signal like the DVK is. Unless you have tapes that are in very poor condition, such tapes will play with problems of some kind no matter what player you use, so an external frame-level tbc might be needed at times to help prevent bad sync and dropped frames. In those cases I'd suggest either the ES15 to get some additional frame timing enforcement, or the DVK. But not both. Two frame tbc's wouldn't be of any use anyway, because the corrections made by the first frame tbc would prevent the second tbc from doing anything.

In any case, the poc amp would be the last component in line. It's used mostly to correct the signal level. For color, they are OK for correcting an obvious or severe color problem that exists throughout the length of the tape and doesn't change much over time. But usually you find that when color is corrected for one scene or one segment, the color balance or hue changes from segment to segment. It's a common problem with VHS, which is not very consistent. Another problem with YUV color correction is that correcting one color un-corrects the other colors, or correcting something like the color of brights will introduce a color cast into the color of darks. You could make those same corrections later in RGB, because RGB allows correction of distinct colors and distinct color ranges without affecting other colors or parts of the image.

[lordsmurf]

Replying as I read...

Lights always have color issues.
I see no bleed by letters, just ghosting caused by the recording, lousy overlay.
I see some timing wiggles, TBC off?
Audio is hollow.

I doubt it's the players, usually the recording has it burned in.

AG-1980P probably lacks ghosting. Maybe the ES15 might add it, maybe, not the DVK-100.

If this is post-denoise clip, it could be user error. We need to see raw capture clip.

Don't crop. You've going to make your life miserable if you do. The video is 3:2 store, but 4:3 aspect. So 8x8 crop will make a mess. It's not that easy, reason you should just mask.

I've never seen 1980 bad caps cause ghosting. Usually far worse issues, mostly color or signal at all.

2nd clip is the same errors.

When using ES15, VCR TBC must be disabled. At that point, VCR mostly used for transport and any non-TBC DNR features. So still good VCR, even with TBC off in those cases.

I'd never used the DVK-100 as a proc amp, and have sold all them now (so can't test). I did play with it some, but didn't take notes. Didn't have time. You should capture video while fiddling with it, share that here, let us see abilities. I need to do that with my own sometime. I have BVP4, TBC-3000, SignVideo, etc -- enough proc amps already, another reason I didn't test the DVK.

Lagarith is better than MagicYUV, 2nd choice to Huffyuv for me.

ES15 acts as pre-filter for DVK as TBC. DVK has weaker TBC than TBC-1000/etc, needs the pre-clean. It's a good solution that had been more readily available, as well as cheaper. Even that TBC(ish) solution is drying up, much like the "real" TBCs. You needed it. Can't capture without TBC.