The present invention provides an image processing method which includes recording an image by irradiating a recording medium with laser beams which are arrayed in parallel at predetermined intervals to heat the recording medium, so that the image is composed of a plurality of lines written with the laser beams on the recording medium, and wherein in the image recording, the plurality of lines written with the laser beams include a line written first and an overwritten line, a part of which is overlapped with the line written first; and the irradiation energy for the overwritten line is smaller than the irradiation energy for the line written first.