hi all,
As my experience with bttv is limited to Grandtec cards (very cheap) I would like to know if high resolution captures always do this:
2 images are interlaced in 1 and the effect I see my hand in 2 distinct positions.
my card has 4 inputs, 1 BT878 chip. res: 768x576 colours, 24 bit.
that code doesn't help my case:
http://www.zoneminder.com/forums/viewto ... interlaced
Does every bt878 chip based card do that at high resolutions or should I blame my card?
davide,
interlaced images
interlaced images
Last edited by davide on Mon Jun 07, 2004 4:46 pm, edited 2 times in total.
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lazyleopard
- Posts: 403
- Joined: Tue Mar 02, 2004 6:12 pm
- Location: Gloucestershire, UK
Yes. The interlaced half-frames are 1/50th (for PAL, or 1/60th if it's NTSC) of a second apart, so if the subject has moved in that time then you will see a doubling of the image. With standard TV cameras there's no way of avoiding the interlacing, as that's the way the cameras do things. It's als the reason a dedicated digital webcam will usually get a clearer image; it's reading the CCD in one sweep.
Rick Hewett
It's a shame there aren't any progressive-scan CCTV cameras and capture boards. 
I want to set up a large installation (as many as 8 cameras), and interlace is one of the things that's been bugging me. Axis and some other companies make network cameras that can capture progressive frames, but models suitable for outdoor use and full framerates cost a fortune.
USB is out of the question because the cable distances are too limited. I need some cable runs up to around 170 feet. It would be necessary to locate a small computer next to each camera (or use very expensive extenders). And of course, most USB webcams are of such poor quality anyway, that there isn't really any point.
Has anyone else done any legwork to find a cost-effective way to do progressive-scan surveillance?
I want to set up a large installation (as many as 8 cameras), and interlace is one of the things that's been bugging me. Axis and some other companies make network cameras that can capture progressive frames, but models suitable for outdoor use and full framerates cost a fortune.
USB is out of the question because the cable distances are too limited. I need some cable runs up to around 170 feet. It would be necessary to locate a small computer next to each camera (or use very expensive extenders). And of course, most USB webcams are of such poor quality anyway, that there isn't really any point.
Has anyone else done any legwork to find a cost-effective way to do progressive-scan surveillance?
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kim_asplund
- Posts: 33
- Joined: Tue Dec 16, 2003 1:51 pm
There is available casings for cameras to use outdoors cost about 60€ here in Finland. And the casings are available with or without cooling or heating. Dont see any reason why you could not putt an axis indoor camera in one of those.
http://www.velleman.be/common/product.A ... &id=340007
if you really want to go out on the lim using usb cameras you can use an standard cat5 to fiber converter (cost a smal fortune) and make a usb-cat5 adapter. they convert basicly all signals that ar fed to them. then i guess you can get usb working ~1km++ away lol.
(BNC to fiber converters are available to)
http://www.velleman.be/common/product.A ... &id=340007
if you really want to go out on the lim using usb cameras you can use an standard cat5 to fiber converter (cost a smal fortune) and make a usb-cat5 adapter. they convert basicly all signals that ar fed to them. then i guess you can get usb working ~1km++ away lol.
(BNC to fiber converters are available to)