1. A method of tint generation, comprising the steps of: (1) preparing an original image bearing contour lines thereon which define respective regions of said original image; (2) scanning said original image for obtaining pixel data thereof; (3) converting said pixel data into binary data with reference to a predetermined threshold level, thereby discriminating pixels of said contour lines from other pixels of said original image; (4) thickening of the contour lines by processing the binary data, thereby connecting gaps in the contour lines to form closed regions; (5) converting said binary data into first run-length data; (6) displaying a display image on a display means in response to said first run-length data; (7) designating desired colors to respective regions of said display image corresponding to the regions of the original image while monitoring said display image; (8) affixing color code data representing the desired colors to said first run-length data in accordance with the designation of said desired colors to the respective regions of the display image, thereby obtaining second run-length data; (9) obtaining recording data, representing halftone-dot percentages corresponding to one or more color separations, on the basis of said color code data affixed to said second run-length data; and (10) recording one or more color separations on a photosensitive material in accordance with said recording data, wherein the one or more recorded color separations can be used to produce an output image in which regions corresponding to the regions of the original image have tints corresponding to the desired colors designated to the respective regions of the display image.