A camera microcomputer sets a gamma characteristic that suits a luminance input value/output value relationship in the entire luminance region extending from lower luminance to higher luminance of a video signal to a luminance input value/output value relationship of a referential gamma characteristic, irrespective of input dynamic range. A gamma correction processing unit performs gamma correction processing on a captured video signal in such a way as to convert the input value into the output value based on the set gamma characteristic.