n00bzor Posted March 21, 2009 Report Share Posted March 21, 2009 Hey, i'm obviously trying to acquire images with a usb camera. Using LV8.5. Vision 8.5 and the usb drivers installed. My program is supposed to take pictures continously with the camera and dump testX.jpg in a folder, where X is the number of the picture taken. Problem is it only works for 1 in 100 or 200 or 300 pictures (i can't seem to get a pattern, it's a random thing). I only get one valid image, the rest are black. I think it has to do with synchronising the camera with the vi. Any ideas? Thanks in advance. Quote Link to comment
n00bzor Posted March 21, 2009 Author Report Share Posted March 21, 2009 Fixed : i was using snap instead of grab. Quote Link to comment
menghuihantang Posted March 21, 2009 Report Share Posted March 21, 2009 QUOTE (n00bzor @ Mar 20 2009, 06:07 AM) Hey, i'm obviously trying to acquire images with a usb camera. Using LV8.5. Vision 8.5 and the usb drivers installed. My program is supposed to take pictures continously with the camera and dump testX.jpg in a folder, where X is the number of the picture taken.Problem is it only works for 1 in 100 or 200 or 300 pictures (i can't seem to get a pattern, it's a random thing). I only get one valid image, the rest are black. I think it has to do with synchronising the camera with the vi. Any ideas? Thanks in advance. I have the same problem too. I use the Microsoft LifeCam. But not as bad as 1 in 100, it returns a black image maybe once every 200 so. I don't know if it is a synchronising problem, but it is definitely related to the webcam settings. It seemed to me that every time the webcam snaps an image, it auto-adjusts itself for the environmental light and very likely it returns an error at this point. So I turned off its auto-white-balance and reset up other parameters like saturation, contrast. This helps a lot, but I don't know if it can help you. Just in any case the webcam still returns a black image, I put a while loop around image snap routine which only stops after an non-black image is captured. Quote Link to comment
deep Posted May 26, 2009 Report Share Posted May 26, 2009 QUOTE (n00bzor @ Mar 20 2009, 04:37 PM) Hey, i'm obviously trying to acquire images with a usb camera. Using LV8.5. Vision 8.5 and the usb drivers installed. My program is supposed to take pictures continously with the camera and dump testX.jpg in a folder, where X is the number of the picture taken.Problem is it only works for 1 in 100 or 200 or 300 pictures (i can't seem to get a pattern, it's a random thing). I only get one valid image, the rest are black. I think it has to do with synchronising the camera with the vi. Any ideas? Thanks in advance. hi can u send me ur code........ i need it very urgently please Quote Link to comment
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