Waviness in image - can anything be done about this?

[brassplyer]

From a DVD made from a VHS capture, this is after cleanup with NeatVideo. This banding/waviness shows up in places - comes and goes. Wondering if anything can be done about it. I don't have access to the original VHS. What's the "official" term for it and what causes it?

Thanks.

[jagabo]

Don't vertically resize interlaced video unless you know what you're doing.

[brassplyer]

Don't vertically resize interlaced video unless you know what you're doing.

Has nothing to do with resizing, it's in the original DVD image which appears to have been just a straight capture & convert without even taking out the switching noise at the bottom.

[jagabo]

Then whoever made the DVD resized. You're screwed.

[brassplyer]

Then whoever made the DVD resized. You're screwed.

I'm pretty close to positive they didn't. It's taken off a several generations old VHS copy probably converted from PAL (?) since it was originally broadcast on Japanese tv in the early 70's. From the looks of things just converted to DVD with no tweaking or cropping whatsoever.

As I say, it's not consistent, it's just in certain spots.

[smrpix]

Those horizontal lines are what happens when you resize interlaced video, as jagabo said. Protest as long as you like, that's what we're seeing.

Please post a short clip if you think it will show something different.

[jagabo]

The only way to get rid of them is to vertically blur them until they go away. Then your left with blurry, double exposures rather than wiggly lines.

Lanczos4Resize(width,height/4).Lanczos4Resize(width,height)

[brassplyer]

Please post a short clip if you think it will show something different.

No, what you see in the screen shot is what you see in the video.

[jagabo]

No, what you see in the screen shot is what you see in the video.

Are you sure? Obviously, the DVD wasn't encoded at 432x288. Was it resized during playback or by whatever program you used to make the image?

[vhelp]

if you want to get a better truer image for members to give their views on, D/L the virtualdub-MPEG2 1.6.15 and drag your mpeg file into it and scrub to the frame(s) you want to snip, without any filtering, and (Ctrl+1 is the unfiltered pain, 2 is the filtered) and save as PNG and then post them. at least we won't think you or your software player/editor is adding to problem.

https://www.videohelp.com/download/VirtualDub-MPEG224586%20.zip

i use these two all the time for quckies: { ffplay (part of ffmpeg package) and mplayer } are easy players that you can drag/drop most files to in order to quckly view and analize them in a hurry. i have their shortcut icons on my desktop for quick drag-drop.

[DB83]

By any chance, is this the dvd you were talking about in the field-order topic ?

Echoing what others have said, we really need to see an actual example of the video both BEFORE and AFTER editing just incase you have also introduced artifacts in to play.

[brassplyer]

No, what you see in the screen shot is what you see in the video.

Are you sure? Obviously, the DVD wasn't encoded at 432x288. Was it resized during playback or by whatever program you used to make the image?

I made a screen cap with PaintShop Pro and saved to jpg just to show the artifact. I reduced the size just to not have this big cap in the thread, it wasn't necessary to show the problem.

I don't know what resizing would have accomplished. All the border junk is still in place in the original video. Perhaps something happened in the conversion process from whatever the original Japanese format was?

For my edification, what's considered the right way to crop interlaced video? I've cropped things to get rid of border noise and never had this happen. I've just always made sure I cropped each axis to an even number and resized back to 720x480.

[jagabo]

Cropping doesn't cause that co-mingling of the two fields, resizing vertically does.



You mentioned PAL/NTSC conversion -- the problem could have happened there. BTW, Japan used to broadcast in NTSC-J. The same as NTSC-M, but without 7.5 IRE setup (darker black level).

I made a screen cap with PaintShop Pro and saved to jpg

Screen cap of what? A media player may have been resizing for display.

[brassplyer]

Cropping doesn't cause that co-mingling of the two fields, resizing vertically does.


[Attachment 22086 - Click to enlarge]

Going by what you're showing in the above pic, that's a different issue than the waviness in the video I'm referring to.

[smrpix]

Please post a short sample. The improperly resized interlacing in the screen grabs is overpowering any other issues.

[jagabo]

Cropping doesn't cause that co-mingling of the two fields, resizing vertically does.


[Attachment 22086 - Click to enlarge]

Going by what you're showing in the above pic, that's a different issue than the waviness in the video I'm referring to.

It's exactly the same thing as in your sample picture. The thickness of the wavy bars varies depending on how much resizing you do. But we'll never know for sure because you won't post a sample of the video.

[brassplyer]

Going by what you're showing in the above pic, that's a different issue than the waviness in the video I'm referring to.

It's exactly the same thing as in your sample picture.

See how the edges of all the elements the image in the sample you put up are all drastically skewed? Which I assume is that way throughout the video. That never happens to the images in the video I'm working on. And it's only in a few spots. It seems almost like some kind of noise that got introduced. While I can't say for sure what it is (which is why I'm asking) I really don't think it's the same issue as seen in the sample screen shot you put up.

[brassplyer]

if you want to get a better truer image for members to give their views on, D/L the virtualdub-MPEG2 1.6.15 and drag your mpeg file into it and scrub to the frame(s) you want to snip, without any filtering, and (Ctrl+1 is the unfiltered pain, 2 is the filtered) and save as PNG and then post them. at least we won't think you or your software player/editor is adding to problem.

Mpeg frame off the DVD and then the cleaned version. The artifact is clearly visible in the unprocessed DVD frame.

[poisondeathray]

Are you referring to 1) the background "waves" or 2) the "notching" from the improper interlaced resize ?





Notice your recent screenshots don't show #2 (because it hasn't been resized)

[brassplyer]

But we'll never know for sure because you won't post a sample of the video.

Uno momento.

[brassplyer]

Are you referring to 1) the background "waves" or 2) the "notching" from the improper interlaced resize ?


[Attachment 22102 - Click to enlarge]



Notice your recent screenshots don't show #2 (because it hasn't been resized)

The background waves. The original full size frame looks identical. The recent shots do show interlace combing, it just happens to be in a place where there's less motion and it's less obvious. Look at the top of the mic.

[poisondeathray]

The background waves. The recent shots do show interlace combing, it just happens to be in a place where there's less motion and it's less obvious. Look at the top of the mic.

Yes, but that combing is "normal" for interlaced content in those last 2 screenshots. You're viewing 2 fields representing different moments in time

Your 1st screenshot in the opening post is "not normal" and has not been resized properly - that' s what led everyone off track .

If you view the fields separately you will see the difference

[jagabo]

Are you referring to 1) the background "waves" or 2) the "notching" from the improper interlaced resize ?

The background waves.

Thanks for being completely vague in your earlier posts. The background waves are just analog noise recorded onto tape. Go record a tape with a vacuum cleaner running right next to it. You'll probably get similar noise. Something wasn't properly grounded, some strong electromagnetic device was running nearby, or the analog recording device was defective.

[brassplyer]

The background waves are just analog noise recorded onto tape.

"...and which brings us back to do....oh, oh, oh."


Are you aware of a filter which will get rid of such noise?

[poisondeathray]

What is the pattern ? Does it move and at what frequency or speed ?

You can try fanfilter or neuralnet , but I suspect it will be hard to treat without turning the image to mush

http://www.avisynth.nl/users/vcmohan/FanFilter/FanFilter.html
http://www.avisynth.nl/users/vcmohan/NeuralNet/NeuralNet.html

[jagabo]

Neat video is designed to deal with that type of noise. Simple bob of your sample image followed by low frequency smoothing with Neat Video:

[brassplyer]

What is the pattern ? Does it move and at what frequency or speed ?

You can try fanfilter or neuralnet , but I suspect it will be hard to treat without turning the image to mush

http://www.avisynth.nl/users/vcmohan/FanFilter/FanFilter.html
http://www.avisynth.nl/users/vcmohan/NeuralNet/NeuralNet.html

Here's a 7 sec sample I carved out with Vegas Pro. It's been reconstituted but looks like the original for all intents and purposes.

[brassplyer]

Neat video is designed to deal with that type of noise. Simple bob of your sample image followed by low frequency smoothing with Neat Video:

Thanks! I'll give it a shot. I'm very much still learning to steer NV.

[brassplyer]

Neat video is designed to deal with that type of noise. Simple bob of your sample image followed by low frequency smoothing with Neat Video:

Can you be a bit more specific about what you did? You say you did a bob, which in essence means you deinterlaced it?

I find I might reduce that waviness in spots on video but not consistently throughout.

[jagabo]

Neat video is designed to deal with that type of noise. Simple bob of your sample image followed by low frequency smoothing with Neat Video:

Can you be a bit more specific about what you did? You say you did a bob, which in essence means you deinterlaced it?

The bob was just for the demo. Seeing only one field makes it easier to see that the noise is greatly reduced without destorying the rest of the image. When processing your video you can just use NV in interlaced mode. Or if you're deinterlacing anyway (with QTGMC or whatever) you can apply NV while the video is deinterlaced.

I find I might reduce that waviness in spots on video but not consistently throughout.

You need to train NV for the noise in each specific shot. And only apply it to those shots.