Configurable image sensor

An apparatus comprising:

• a photodiode;
• a charge storage unit including a floating drain;
• a quantizer;
• a controller configured to:
• receive programming data;
• determine, based on the programming data, at least one of:
• an integration period in which the charge storage unit including a floating drain accumulates charge received from the photodiode, or a number of times of sampling the charge received from the photodiode;
• enable the photodiode to accumulate residual charge, and to transmit overflow charge to the charge storage unit after the photodiode saturates;
• control the charge storage unit to accumulate at least a part of the overflow charge received from the photodiode within the integration period;
• and
• control the quantizer to:
• sample the at least a part of the overflow charge or the residual charge for the number of times to obtain the number of samples, and
• quantize the number of samples to generate the number of quantization results.