To simplify the conversion processing and to attain high speed processing in the case of converting picture element density attended with magnification or reduction in an equipment conducting image processing with digital signal processing for a wordprocessor or a copying machine or the like.
When a magnification of a converted image with respect to an original image is expressed by natural numbers being prime to each other, a picture element conversion section 5 obtains a density calculation equation used for a relative position relation of a picture element of a converted image with respect to a picture element of an original image repeated periodically and for a density of plural adjacent picture elements of the original image surrounding each picture element when the converted image is projected onto the original image to obtain a table and it is stored in a table memory 15. In the case of actual conversion processing, after a relative coordinate for each picture element is obtained, the density calculation equation is not obtained and a table is referred to read the density calculation equipment from a residue of dividing the coordinate of each picture element of the converted image by a magnification, the density of an adjacent picture element is substituted to the density calculation equation to calculate the density of each picture element of the converted image.
KITAMURA YOSHIHIRO
NAKAMURA YASUHISA
ONO MICHIHIRO
