an active pixel sensor imaging device comprises array of pixel cells , each pixel cell providing a pixel output signal to a signal output line associated therewith . each pixel cell comprises : a photosensor having at least two independent portions , each independent portion having a sensor output ; and , a separate readout circuit coupled to the sensor output of each independent portion . each separate readout circuit has an output coupled to the signal output line and each separate readout circuit is capable of generating an output signal at the output . the outputs of the separate readout circuits for the pixel cell are connected such that the output signals are combined in an additive manner to produce the pixel output signal . hardware and software correction methods are provided for the correction of defective pixels in monochromatic and color imaging systems .