An imaging apparatus includes a photoelectric converter that converts light signals generated from light received by three or more pixels into electric charge signals, each of the electric charge signals corresponding to one of the three or more pixels; an electric charge holder that holds the electric charge signals; an analog selective adder that generates added electric charge signals by adding electric charge signals of certain pixels among the three or more pixels by using analog addition patterns which are rules of adding pieces of electric charge information corresponding to individual positions of the certain pixels; an analog-to-digital converter that converts the added electric charge signals into digital signals; and an addition data compressor that compresses the digital signals by using a total number of pixels for which pieces of electric charge information are added in the analog addition patterns and thereby generates compressed digital signals.