Image processing method, and image processor

An image processing method, comprising:

• any one of recording an image on a thermally reversible recording medium that can reversibly change any one of its transparency and color tone depending on temperature by irradiating and heating the thermally reversible recording medium with a laser beam, and
• erasing the image recorded on the thermally reversible recording medium by heating the thermally reversible recording medium,
• wherein a light irradiation intensity I1 at a center position of the laser beam irradiated in the image recording and a light irradiation intensity I2 on an 80% light energy bordering surface to the total light energy of the irradiated laser beam satisfy the expression, 0.40≦I1/I2≦2.00;
• in the image recording, a first auxiliary line extended by a predetermined distance from a start point of each of image lines among a plurality of image lines constituting an image in the opposite direction from the scanning direction and a second auxiliary line extended by a predetermined distance from an end point of each of the image lines in the scanning direction are prepared, and when the first and second auxiliary lines including an image line are continuously scanned from the start point of the first auxiliary line to the end point of the second auxiliary line, the image line is scanned with irradiating the laser beam, and the first auxiliary line and the second auxiliary line are scanned without irradiating the laser beam to thereby record the image.