digitalFAQ.com Forum - What caused this banding in the luma on the top field?

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What caused this banding in the luma on the top field?

I captured some VHS home videos several years ago onto my PC with Virtualdub.

I went back to revisit the videos to see if I could improve the quality of the restoration/cleaning.

I discovered that there is banding on the top fields of each frame. The bottom fields look better.

What do you think caused it or is it the fact that these tapes are 30 years old?

The equipment used:

JVC SR-V101US. Can't remember if I used auto or edit, but I know I had the TBC/DNR on.

Capture Device

Ati TV Wonder 600 USB. Only setting I changed, was putting sharpness at 0.

AVT-8710 (My TBC does have the hanging/jumping frames, but usually no more than the first 5 seconds of the video.) I adjusted the brightness and contrast.

You can clearly see the banding each alternating field if you load the avs file in Virtualdub and increase the size to 200%.

Code:

AviSource("test.avi") # 1s clip of a VHS tape filmed in 1985

AssumeTFF()

SeparateFields()



# Got this from Jagabo at Videohelp

# Show Luma and map Chroma to luma in separate clips so we can see each plane.

#Y=ColorYUV(off_u=-256, off_v=-256).ColorYUV(off_u=128, off_v=128)

#U=UtoY()

#V=VtoY()



#StackHorizontal(Y, U, V)

You wouldn't happen to know what kind of camcorder this was recorded with? I have footage from a circa 1987 Sears LXI Series (actually made by Hitachi) that exhibits the same banding pattern. One field has oddball chroma (luma is unaffected), the problem was the camcorder's sensor apparently. I ruled out the rest of the workflow systematically.

The camcorder I had was also sold under the RCA brand and Radio Shack's Realistic brand as well. If you can show a screenshot with the camera's date function turned on, it might give a hint to the brand used.

I don't have any tapes with the date/time showing and my uncle no longer has the camcorder nor remembers the model.

I don't see any banding when the video is played normally.

I actually noticed it when I converted the video to 60 fps with:

Code:

YadifMod(mode=1,edeint=nnedi3(field=-2))

Every other frame looked bad.

I noticed it when the video was played back on a progressive display, even without any deinterlacing. You could see one field had slightly different color from another. It is completely unnoticeable on a CRT. I still have the camcorder and will be trying raw captures direct to see if its the image sensor.

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