I have Microsoft HD3000 lifecam studio webcam. I have some noise, when operating it in low light conditions. I would like to minimize noise as much as possible, detaching infrared filter and using it as a grayscale imaging device.

As a software engineer i could go simple way: I could suppress noise to some degree purely with software means. Applying some lowpass filtering between frames to suppress high frequency noise, suming UP R+G+B channels to get grayscale image, or further - decreasing its resolution 2 times (via adding 4 nearest pixels' brightneses, so gaining extra bit depth in exchange for resolution) But that's not point of question.

But I think I could achieve some SNR improvements in hardware circuitry itself. I suspect noisy ATX PSU is main reason of such noise (400W of constant load, constant writes to hard drives, so on) So some noise could possibly go to web cam, messing up with exposure process itself.

So i would like to try to power my webcam from separate power source. (Dual 18650 li-ion batteries in series) I suppose to connect web camera USB power pins to a li-ion accumulators, via LM7805(http://www.kynix.com/Detail/800063/LM7805.html) 1A linear regulator. So now you got the idea, and my questions are as follows:

    1.Can be "1A" considered suffient current?
    2.Is it safe to operate camera in such way?
    3.Is it safe to connect just D+ and D- pins to PC?
    4.Could I achieve some noise suppression this way? (If not - why?)