| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a forgery prevention pattern generating method and a forgery prevented printed mater for preventing forgery by processing, on a computer, duplicates generated by a copying machine or images fetched by a digital scanner and a digital camera, etc. SOLUTION: Image data for generating forgery prevention pattern are fetched (step S1) and the image data are divided into blocks in the same shape (step S2). Then, in how many gradations the fetched image data are to be expressed is decided and different gradation patterns for the number of the gradations are prepared (step S3). The density information of the respective blocks is evaluated on the basis of the decided number of the gradations (step S4) and replacement with the gradation pattern is performed on the basis of the evaluated result (step S5). When the replacement with the gradation pattern is ended, the end part of the gradation pattern of the adjacent block is connected, a film original plate is outputted and a press plate processing is performed on the basis of the film original plate (step S6). Thus, by gradation-expressing the forgery prevention pattern by a plurality of continuous lines, the forgery prevention pattern whose forgery is difficult is prepared easily.</p> |
