PURPOSE: To correctly grasp the colored state and check a vegetable or a fruit with high precision regardless of its shape or colored state by comparing the color value of each unit picture element of a photographed color image with the reference color value of the corresponding picture element.

CONSTITUTION: A vegetable or a fruit 2 radiated by a light source 1 is photographed by a color camera 3, and an image processing computer 4 processes the image and outputs it to an image output device 5. The reference color value of each unit picture element of the standard color distribution pattern corresponding to the vegetable or the fruit 2 is stored in an image memory 6 in advance. The computer 4 compares the color value of each unit picture element of the photographed color image with the corresponding reference color value and judges the quality of the vegetable or the fruit 2 based on the result. The colored state can be correctly grasped, and the quality can be judged with high precision even if the shape and colored state of the vegetable or the fruit 2 are complex.