METHOD AND DEVICE FOR MOIRE REMOVAL FROM DOT IMAGE, AND COMPUTER-READABLE RECORDING MEDIUM STORED WITH MOIRE REMOVING PROGRAM FOR DOT IMAGE

摘要

PROBLEM TO BE SOLVED: To speedily remove moire without defocusing an image of an edge part by deciding the similarity between a dot of interest and a dot in its nearby area according to the density values of the dots, calculating the mean value of density value of other dots according to the similarity, and varying the density value of the dot of interest according to the mean value. SOLUTION: A dot feature point extraction part 121 stores a storage part 20 with the ratio of the number of dots forming the dot of interest and the area that four adjacent dots surrounding it form as the density value of the dot of interest. A dot similarity decision part 122 calculates the ratio of the density values of the point of interest and other dots in the nearby area and compares it with a threshold value set previously in a parameter setting part 126. A dot feature decision part 123 decides that a nearby dot exceeding the threshold value is outside the border of the edge part, excludes the density value of the dot, and finds the mean of density values of only nearby dots less than the threshold value. A dot pixel number variation part 125 varies the number of dots so that the density value of the dot of interest approximates the mean value.