1. A control system for a camera unit to generate a processed digital image represented by a plurality of image pixels, the control system comprising: an ambient light sensor for generating an ambient light data signal representative of an intensity of ambient light detected; a camera controller coupled to the ambient light sensor and for adapting the camera unit to a mode of operation selected from a plurality of modes of operation defined for the camera unit in relation to the intensity of the detected ambient light, the plurality of modes of operation comprising a first mode of operation and a second mode of operation; and a camera sensor coupled to the camera controller to receive a control signal generated by the camera controller indicating the selected mode of operation, the camera sensor comprising: an image sensor comprising a plurality of pixels for providing image data representing a scene image exposed to the image sensor, the image data comprising color image data and infrared image data; and an image sensor processor responsive to the control signal to process the image data into the processed digital image, according to the selected mode of operation, by determining a plurality of processed color component values used to represent full colors in the processed digital image, for each image pixel of the processed digital image (i) in the first mode of operation, based on the color image data without using the infrared image data, and (ii) in the second mode of operation, based on the color image data modified by the infrared image data.