PURPOSE: To extract the characteristics of various objects to be photographed effectively, by synthesizing the binary coded signal whose contour is intensified by differentiation and the like and the binary coded signal of an original image signal by an exclusive OR circuit.

CONSTITUTION: The output from an image sensor 6 is inputted into a contour intensifying circuit 16 through an waveform shaping circuit 12. The output thereof is coded into the binary value by the binary coding device 8. Meanwhile, the output of the waveform shaping circuit 12 is supplied to another binary coding device 19 and an integrating circuit 20. The integrating circuit 20 is constituted by a resistor R and a capacitor C, and its output is inputted into the binary coding device 19. The image signal, which is inputted into the integrating circuit 20, is averaged by the integrating circuit 20, and the averaged value becomes an reference voltage U for the binary coding device 19. The outputs of the two binary coding devices 19 and 8 are inputted into the exclusive OR circuit 21, and its output is inputted into a distributing device 9.