Image Noise
Posted: 02 February 2010 11:24 PM   [ Ignore ]
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I just got one of these cameras, and I’m just wondering if the following image is representative of the amount a normal amount of noise.

2py8875.jpg

This image is taken at 640x480@75fps with the gain turned to max. I covered the camera with my hand.

Even at 640x480@30fps I still get a fairly large amount of noise until I turn the gain down to nearly nothing.

Just curious if this is how the camera should perform or if I should exchange it.

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Posted: 02 February 2010 11:41 PM   [ Ignore ]   [ # 1 ]
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zrbarnes - 02 February 2010 11:24 PM

I just got one of these cameras, and I’m just wondering if the following image is representative of the amount a normal amount of noise.

This image is taken at 640x480@75fps with the gain turned to max. I covered the camera with my hand.

Even at 640x480@30fps I still get a fairly large amount of noise until I turn the gain down to nearly nothing.

Just curious if this is how the camera should perform or if I should exchange it.

This is normal. You should always keep the camera gain to 0. The gain is the artificial amplification of sensor data after it has been captured. As CMOS sensors do not perform very well in dark conditions, setting gain to the max will basically amplify the noise. The 75fps is above the max rated fps for this sensor (60fps @ 640x480). What are you trying to accomplish with this ‘test’?

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Posted: 02 February 2010 11:53 PM   [ Ignore ]   [ # 2 ]
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Thanks for the advice.

This test was to just create the worst case scenario. When I originally installed the driver, skype was defaulting to a high framerate, and I was getting similar amounts of noise. Recent releases have improved this.

Unfortunately, even with 640x480@30fps with the gain set to 0, my well lit room turns into a dimly lit dungeon.

15xnacm.jpg

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Posted: 03 February 2010 12:09 AM   [ Ignore ]   [ # 3 ]
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zrbarnes - 02 February 2010 11:53 PM

Thanks for the advice.

This test was to just create the worst case scenario. When I originally installed the driver, skype was defaulting to a high framerate, and I was getting similar amounts of noise. Recent releases have improved this.

Unfortunately, even with 640x480@30fps with the gain set to 0, my well lit room turns into a dimly lit dungeon.

Try this:
- Disable auto exposure mode and set exposure to the maximum.
- Disable auto gain mode and set gain to the minimum.

It this does not improve the brightness of your image, then slowly raise the gain.

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Posted: 03 February 2010 12:19 AM   [ Ignore ]   [ # 4 ]
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That’s actually what I currently have it set on (and what it was set on when I took that screen cap).  The grain is bearable up to about the halfway mark, I was just hoping to get a little bit better quality image out of it.

I suppose I’ll just have to live with the grain, or get brighter light bulbs (maybe a halogen lamp, haha).

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Posted: 03 February 2010 12:33 AM   [ Ignore ]   [ # 5 ]
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zrbarnes - 03 February 2010 12:19 AM

That’s actually what I currently have it set on (and what it was set on when I took that screen cap).  The grain is bearable up to about the halfway mark, I was just hoping to get a little bit better quality image out of it.

I suppose I’ll just have to live with the grain, or get brighter light bulbs (maybe a halogen lamp, haha).

The camera is actually pretty sensitive to the light. I’m not sure why you’re getting this kind of dark capture performance. What is your frame rate set to?

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Posted: 03 February 2010 12:51 AM   [ Ignore ]   [ # 6 ]
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Ah, so maybe I do I have a problem then. That picture was taken with the video pin set to 640x480@30 fps.

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Posted: 03 February 2010 01:02 AM   [ Ignore ]   [ # 7 ]
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zrbarnes - 03 February 2010 12:51 AM

Ah, so maybe I do I have a problem then. That picture was taken with the video pin set to 640x480@30 fps.

At 30fps the image should be bright. At higher frame rates the brightness diminishes because the the exposure gets shorter.

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Posted: 10 May 2013 06:22 PM   [ Ignore ]   [ # 8 ]
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I detect very bad image quality with this as well. The Image noise, some straight lines going from bottom to top on certain FPS, and also that noise is blinking :/

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