Patent ID: 7307758

Claim:
An image forming apparatus, comprising: a determination section which determines a kind of an original to be one of a color original, a monochromatic photo original and a monochromatic character original; a mode setting section which sets a first image-quality preference mode that places higher priority on image quality than on a processing speed of an image data when the kind of the original is determined to be the color original, sets a second image-quality preference mode that places higher priority on the image quality than on the processing speed of the image data when the kind of the original is determined to be the monochromatic photo original, and sets a processing speed preference mode that places higher priority on the processing speed of image data than the image quality when the kind of the original is determined to be the monochromatic character original; a first processing section which is input the image data of the original, subjects the input image data to an M-bit process at a first processing speed V 1 , and outputs a first image data, in the processing speed preference mode; a second processing section which is input the image data of the original, subjects the input image data to an N-bit (M<N) process at a second processing speed V 2 (V 1 >V 2 ), and outputs a second image data, in the first and second image-quality preference modes; a compression/decompression section which is input the first image data and processes the input first image data in a first compression/decompression method, in the processing speed preference mode, and is input the second image data and processes the input second image data in a second compression/decompression method, in the first and second image-quality preference modes; a parameter setting section which sets a parameter necessary for the processes of the first processing section and the second processing section, in accordance with the mode set by the mode setting section; a histogram calculation section that generates a histogram from the data of the original to cause the determination section to determine the kind of original based on the histogram; a color CCD scan processing section that processes color image data acquired from a color CCD sensor; and a monochromatic CCD scan processing section that processes monochromatic image data acquired from a monochromatic CCD sensor; wherein a control section selects, based on said determination, the image data processed by at least one of the color CCD scan processing section and the monochromatic CCD scan processing section and delivers the selected image data to the first processing section and the second processing section.