Abstract: An image is recorded on a transparent heat sensitive material having a transparent support and a transparent heat sensitive layer disposed on the transparent support. The transparent heat sensitive material is moved in an auxiliary scanning direction. Image information is recorded on the transparent heat sensitive material in a main scanning direction substantially normal to the auxiliary scanning direction with a thermal head having an array of as many heating elements as the number of pixels along the main scanning direction, so that the transparent heat sensitive material is two-dimensionally scanned to record an image in an image area thereon. A non-image area of the heat sensitive material other than the image area thereof is recorded at a predetermined density level. The array of heating elements has a length larger than the width of the transparent heat sensitive material in the main scanning direction, so that the entire surface of the non-image area can be recorded at the predetermined density level.

Abstract: An image is recorded on an image recording material by energizing a thermal head having a plurality of heating elements with input image data. As the image recording material, there is employed a heat sensitive recording material comprising a support coated with a coating solution which makes an unheated area colored and a heated area transparent in a colorless or light colored manner. An image is recorded on the heat sensitive recording material with the thermal head by processing the image data through negative-positive reversal and applying the processed image data to the thermal head. The image data are processed through negative-positive reversal by converting the image data based on a function which has the input image data as a variable and a negative differential coefficient.