Digital Signal Processing in CCTV Cameras
Digital signal processing a key element of IP camera performance.
Is the signal from an IP camera generated in digital form, or is it converted from an analogue signal after being generated by the camera sensor?
A camera sensor is made up of pixels – each pixel is an active photodiode comprising microlens and filters, amplifier transistor, reset transistor and column bus transistor, with a photodiode on top of a potential well.
Light comes in through the lens, goes through a Bayer colour filter array which arranges RGB colours. It then reaches the photodiodes of the sensor itself and the output voltages are scanned and read and converted to serial.
There’s additional processing in the camera system which tidies up the data after A/D conversion. Typically, the camera engine will do quite a lot of cleaning up and enhancing of the signal in real time. There’s a simplicity to digital states that makes working with them easier than processing analogue signals.