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Outdoor Light Problem In Segmentation

asked 2012-07-30 19:29:25 -0500

erent16 gravatar image

Hi all, I have a problem in my project called by agriculture cv. I have been using PS 3 Eye as a frame grabber. Its sensor is ov534 and it is not able to lighting condition. When i calculate histogram of frame, it gives me false detections in outdoor light conditions. My method is back projection of hue channel after histogram calculating. So how can i solve this problem? Changing camera or color reducing via normalized histogram?

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plant's histogram.

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Entire image's histogram.

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Back Projection Image.

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my working on static image.

On static image, everything is normal but in real time i can not get same results because of camera's motion blur and color changing. In outdoor conditions image shines completely so i only can see red vertical stick on entire image's histogram.

Thanks in advance. Sorry for my bad English.

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Can you post images of the non-static image and its resulting Back Projection Image? It is true that camera quality will affect your algorithm. The overexposure is particularly bad, cameras (cheap) will automatically try to adjust the amount of captured light and you can't control it. Many cameras do a poor job at it and will severely affect most of cv algorithms, specially one based on color like yours.

Rui Marques gravatar imageRui Marques ( 2012-08-01 05:47:32 -0500 )edit

Non-static image shines completely. Its histogram is just red. I have been looking for a new camera. But anyway i try to tune camera parameters.

erent16 gravatar imageerent16 ( 2012-08-02 19:02:38 -0500 )edit

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answered 2012-07-30 20:04:31 -0500

Hi erent16,

My advice would be to purchase a better camera, maybe one of these

Motion blur happens when the objects on the scene moves significantly while camera sensor is still integrating (capturing) the image. To avoid it you should increase the shutter speed.

Also, when the image shines completely is called overexposure. Again, you can reduce its effect by increasing the shutter speed, playing with the gain of the sensor or maybe even with auto-balance

Good luck!

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+1 A better camera would automatically take care about all of this issues!

sammy gravatar imagesammy ( 2012-07-31 01:09:57 -0500 )edit

For now, there is no choice to buy a new camera. Do you have a advise about trying different method in segmentation?

erent16 gravatar imageerent16 ( 2012-08-12 18:47:21 -0500 )edit

Post a picture with motion blur here. But if the images are bad (even you can't see clearly) it's a little chance that an algorithm could do that

sammy gravatar imagesammy ( 2012-08-13 01:39:19 -0500 )edit

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Asked: 2012-07-30 19:29:25 -0500

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Last updated: Jul 31 '12