It is an object of the present invention to provide a method for image processing and an image processing apparatus which are capable of performing repetitive forming and erasing of high-contrast images at high speeds by forming high-density, uniform images and uniformly erasing images in a short period of time, and in addition, suppressing the degradation of the thermoreversible recording medium due to repetitive forming and erasing is possible. The method for image processing of the present invention contains at least any one of image forming step wherein an image is formed on a thermoreversible recording medium in which any one of transparency and color tone is changed reversibly depending on temperatures by heating due to laser beam irradiation, and image erasing step wherein an image formed on the thermoreversible recording medium is erased by heating due to laser beam irradiation to the thermoreversible recording medium, and a light irradiation intensity of the center is equal to or less than the light irradiation intensity of the periphery in the light intensity distribution of cross-section in a direction approximately perpendicular to the traveling direction of the laser beam irradiated at least in any one of the image forming step and the image erasing step.