| 摘要 |
PROBLEM TO BE SOLVED: To accurately decide whether a document is white without being affected by the ground color of the document. SOLUTION: A unit data decision unit 164 decides which of white, gray, and black unit data constituting image data corresponds to. A block decision unit 148 uses decision results of the unit data decision unit 164 to decide luminance section classifications that respective blocks obtained by longitudinally and laterally dividing an image associated with the document belong. When it is decided that the image is a monochromatic image, a mode decision unit 152 further decides features of the document by using the decision results of the block decision unit 148 to decide which of a white-paper document, a gray document and a black-and-white document the document is. When the document is a ground-color document, a digital multifunction apparatus 1 performs preprocessing for removing influence of the ground color and then moves a threshold Y<SB>1</SB>used to classify the unit data by luminance in a direction to black as compared with cases wherein the document is not a ground-color document. COPYRIGHT: (C)2008,JPO&INPIT
|
