Image blurred with Panasonic BL-C1

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jon_benge
Posts: 11
Joined: Tue Mar 06, 2007 11:30 pm

Image blurred with Panasonic BL-C1

Post by jon_benge »

Hi

I've noticed that the captured pictures produced with my Panasonic BL-C1 network cameras often come out blurred (see picture). When standing still, the cameras are able to produce a clear picture. The picture begins to suffer when their is movement, such as people walking down the hallway. It's almost as if the camera is not able to keep up. I was wondering what you might think the cause of this to be? The cameras are quite cheap, they only cost me around £50. Also, the computer which runs ZoneMinder is not exactly state of the art. It's a Pentium 3 ~733MHz w/ 256MB RAM & 20GB HDD (not sure of cache or spindal speed, but probably not very good :D )

Also, suggesting for a minute that it might be the cheapness of the cameras, is there anything I can do in ZoneMinder to improve the picture?

Thanks for reading

Image
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MJN
Posts: 251
Joined: Wed Jan 17, 2007 10:29 am
Location: Wiltshire, UK

Post by MJN »

I see from your other recent post that you're already using the &motion suffix to the source URL although I suspect that only affects the JPEG compression (i.e. 'motion' compresses a lot and quickly, 'clarity' compresses less and more slowly).

The blur is therefore likely a hardware (lens/sensor) issue in that for the fixed aperture size (f/2.8 on the BL-C1) the exposure time has to be long enough to allow sufficient light to the small (less sensitive) sensor.

Presumably if you use the built-in webcam software to capture an image you still get a blurred image? (i.e. ruling out ZM)

In these circumstances it can often help to position the camera to reduce lateral movement of subjects i.e. face-on (parallel) to the direction of motion will reduce image blur. Of course, in this case (a corridor) you've got little choice (although I suppose a lower mounting position might help, but not without its drawbacks).

The BL-C1 does have a 'night view' mode (automatic I believe) hence must be able to perform some auto-exposure hence ensuring the maximum amount of light will help matters (night-mode will inevitably produce more blurring given it has to compensate for the lack of available light).

Mathew
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cordel
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Joined: Fri Mar 05, 2004 4:47 pm
Location: /USA/Washington/Seattle

Post by cordel »

ZM does not change the image as sent from the network cam. I would suspect that the cams shutter speed has slowed down to compensate for low light which will create moving objects to be blurry. Try increasing the light temperarely and see if it improves. A couple people and a flash light would do.
jon_benge
Posts: 11
Joined: Tue Mar 06, 2007 11:30 pm

Post by jon_benge »

Thanks for the information

I will be installing 3 more of these cameras over the next week so i'll get a better idea how the environment and position of the cameras effect the quality of output.

I've switched the URL suffix from &motion to &standard and the results have improved slightly, though still not up to par yet.

I'll also experiment with the built in webcam software and see if I get a better picture. I suppose I could be suffering from bandwith issues but I don't think that's likely. I am on a 100baseT network which comprimises several switches and an IPCop firewall / router.
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MJN
Posts: 251
Joined: Wed Jan 17, 2007 10:29 am
Location: Wiltshire, UK

Post by MJN »

Your network bandwidth shouldn't be an issue as far as individual image quality is concerned (only framerate) as the image you're getting is a fully-packaged JPEG hence the quality received is the quality sent.

What format are you capturing with? nphMotionJPEG or SnapshotJPG? Try one over the other and see if it makes any difference.

Have you also tried the &Clarity suffix for the best-possible image quality?

Mathew
jon_benge
Posts: 11
Joined: Tue Mar 06, 2007 11:30 pm

Post by jon_benge »

MJN wrote:What format are you capturing with? nphMotionJPEG or SnapshotJPG? Try one over the other and see if it makes any difference.
Thanks for the tip. I am currently using the nphMotionJPEG and wasn't aware of the SnapshotJPG option!
MJN wrote:Have you also tried the &Clarity suffix for the best-possible image quality?
Again, I didn't even know this suffix existed! Are there any more you aren't telling me about? :D

I assume from your avatar that you also use, or have used the BL-C1 camera? If it's not too much trouble, would you mind posting a picture of something captured whilst moving, so I can work towards a sort of benchmark?

Once again, thanks
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