Miscoding and misclassification of ischaemic heart disease mortality

Half-tone image data and character image data are discriminated from each other with reference to discrimination data, and are stored separately from each other. In accordance with the image to be printed, one of a character print table and a half-tone print table is selected. In accordance with the result of comparison of the character image data with comparison data read from the character print table, characters are recorded using two kinds of character dot print patterns for recording a dot in the whole area of an associated pixel and for recording no dot. Half-tone images are recorded in the area gradation method using half-tone dot print patterns in accordance with the result of comparison of the half-tone image data with comparison data read from the half-tone print table. One pixel is divided into a plurality of sub-lines. The recording of the characters is performed at intervals of N sub-lines, N is an integer. The recording of the half-tone images is performed at intervals of one sub-line.