Low power and low data-rate imager

An imaging system comprising:

• a pixel array having a plurality of photosensitive elements arranged in a grid formation and being divided into a plurality of groups of photosensitive elements, the photosensitive elements in each group of photosensitive elements being adjacent to one another in the grid formation, the pixel array being configured to output readout voltages proportional to light intensities at individual photosensitive elements in the plurality of photosensitive elements;
• an analog-to-digital converter operably connected to the pixel array to receive the readout voltages and convert the readout voltages into digitized light intensity values;
• and
• at least one processor operably connected to the pixel array and the analog-to-digital converter, the at least one processor being configured to selectively operate each group of photosensitive elements in the plurality of groups of photosensitive elements in one of (i) a high resolution mode in which the pixel array outputs readout voltages corresponding to all of the photosensitive elements in the respective group of photosensitive elements and (ii) a low resolution mode in which the pixel array outputs readout voltages corresponding to only a subset of the photosensitive elements in the respective group of photosensitive elements,
• wherein each group of photosensitive elements in the plurality of groups of photosensitive elements is operable by the at least one processor in both the high resolution mode and the low resolution mode at different times
• wherein the at least one processor is configured to:
• for each group of photosensitive elements in the plurality of groups of photosensitive elements that is operated in the low resolution mode, control the analog-to-digital converter to convert the readout voltages corresponding to the respective the subset of the photosensitive elements in the respective group of photosensitive elements with a first bit depth that is less than a maximum bit depth of the analog-to-digital converter;
• and
• for each group of photosensitive elements in the plurality of groups of photosensitive elements that is operated in the high resolution mode, control the analog-to-digital converter to convert the readout voltages corresponding to all of the photosensitive elements in the respective group of photosensitive elements with the maximum bit depth of the analog-to-digital converter.