| 摘要 |
PROBLEM TO BE SOLVED: To prevent a conversion method of an input image from causing inability of analysis for add-on additional information by selecting an addition method which is proper to a selected image conversion method and adding a prescribed additional information to the image signal. SOLUTION: A received image signal 901 for each color is given to an image- processing section 902, in which 1st or 2nd dither processing is selectively conducted based on a dither processing designation signal 905. After the dither processing, the processed image signal is given to a dot pattern addition section 903. A ROM 906 stores three dot sets, and the adder section 903 adds a dot pattern to the input image signal, only if a color designation signal designates a luminance signal Y and does not add any dot pattern to M, C, Bk signals. Thus, additional information applies add-on to only part of colors that are hardly perceived by human eyes. Then the image signal to which the dot pattern is subjected to add-on is given to a laser drive section, by which printing is conducted. |
