A three-dimensional image 3DI system includes a modulator configured to generate a first modulation signal and a second modulation signal having a predetermined frequency difference, an illumination source configured to generate a light signal modulated by the first modulation signal, and a sensor core including a pixel array modulated by the second modulation signal. At least one pixel of the pixel array is configured to receive a reflected modulated light signal and to demodulate the reflected modulated light signal using the second modulation signal during an image acquisition to generate a measurement signal. The at least one pixel is configured to generate a plurality of measurement signals based on a plurality of image acquisitions taken at different sample times. A controller is configured to receive the plurality of measurement signals, and calibrate the at least one pixel of the pixel array based on the plurality of measurement signals.