To form an image with high image quality without unnatural feeling by specifying, detecting and correcting digital data which are affected by switching noise so as to constitute the digital data smoothly changed as a tone.

A digital data processor includes a means for specifying and detecting a pixel which is affected by the switching noise with respect to the switching noise which is generated when a current fluctuation in the specified tone (a point where the bit transition of 0 and 1 rapidly occurs) of an analog-to-digital (AD) converter enters an analog side as noise to correct the pixel.