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Thin black bars when up-resing to 720p

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Parke Gregg
Thin black bars when up-resing to 720p
on Dec 2, 2008 at 7:35:34 pm

I'm capturing 720p59.94 from a DVcam deck with SDI out using Kona 3's upres. The image quality is good, but thin black bars are being added to the top and bottom. (a little more so to the top) When I view the SDI from the deck, the image is full frame, but when viewing from the Kona and the resulting quicktimes, the black bars are present. It's a problem because the project has several "blur across" dissolves and the blur picks up the black, and also mixed with animation clips that are full frame.

(I see it upresing to 720p and 1080i)

Any ideas on how I can get rid of this during the capture process?

Thanks,
Parke

(edit) I looked at a frame in photoshop and the the resulting image is 1280x711 with 6 pixels of black on the top and 3 on the bottom.



-------Stuck On On--------
Audio and Video Post Production


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Jeremy Garchow
Re: Thin black bars when up-resing to 720p
on Dec 3, 2008 at 3:36:26 am

[Parke Gregg] "Any ideas on how I can get rid of this during the capture process? "

No, that is normal for Sd video, as it rarely is seen raster to raster. You will have to scale up the image a few pixels and then do your dissolve.

Where did the footage orginate (i.e. what camera or source)?

Jeremy


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Parke Gregg
Re: Thin black bars when up-resing to 720p
on Dec 3, 2008 at 3:48:40 pm

The footage is DV shot on a DVX100 with an anamorphic lens. It's coming out of a DSR-2000A deck via SDI.

AJA seems to think this is a result of DV being 720x480 as opposed to 720x486.

Thanks,
Parke



-------Stuck On On--------
Audio and Video Post Production


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Jeremy Garchow
Re: Thin black bars when up-resing to 720p
on Dec 4, 2008 at 7:16:39 am

[Parke Gregg] "AJA seems to think this is a result of DV being 720x480 as opposed to 720x486. "

Sure. And if your program had line 21 on a 486 movie, you'd see a bunch of Pong looking shapes running rampant on the top of your video. When you edited SD, did you ever hit the underscan button on your monitor?

There's a lot of not pretty but very important and informational stuff floating around the edges of video. Also with the 480 to 486 conundrum, there's a few lines of black. THEN if you are up converting to an anamorphic or thin raster codec such as DVCProHD, your video is getting scaled and bent in ways that might make a signal look funny on the edge of the raster.

On an upscale, the entire raster to raster image and all of it's pretty and non pretty images are scaled up within the bounds of a 720 or 1080 vertical pixel count.

Simply scale up your up-converted image a few points to remove it. Or perhaps you can crop a few lines off the top and bottom and leave it 'blank'. Up to you.


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