Image processing apparatus and an image forming apparatus and image processing method comprising the same, image processing program and recording medium

摘要

PPROBLEM TO BE SOLVED: To provide an image processing apparatus, an image forming apparatus and an image processing method that are equipped with the apparatus, an image processing program and a recording medium that are capable of realizing improvement of the image quality by optimum filtering. PSOLUTION: A rising/trailing edges counter section 12 counts the number of the rising and trailing edges in a main scanning and sub-scanning directions inside a pixel block. A filter coefficient setting section 13 calculates the total of edge numbers, and compares the calculated total with a first and second thresholds. When the total exceeds the first threshold, the filter coefficient appropriate to a halftone dot region is selected to hand over a space filter 10. When the total is smaller and not less than the second threshold value, a filter coefficient appropriate to a letter region is selected to hand over the space filter 10. When the total is not more than the second threshold, a filter appropriate to a photograph region and an underlying region or the like to hand over the space filter 10. PCOPYRIGHT: (C)2004,JPO&NCIPI