Defective pixels are to be selected so as not to cause image degradation. A defective pixel correction unit 13 in an image processing apparatus 1 obtains an imaging signal a12 from an imaging sensor 16 via a gain adjustment unit 12, and calculates an absolute value for the pixel value difference between a pixel to be tested for a defect of the imaging sensor 16 and each of its surrounding pixels, respectively. Next, the defective pixel correction unit 13 compares the differential with a defective pixel determination threshold value and determines the pixel being tested as defective, if the differential is greater than the threshold value. It should be noted that the threshold value is changed according to the magnitude of an image transition, by detecting the image transition of a video signal a14 in an image transition detection unit 15.