| 摘要 |
PURPOSE:To decide the classification of a minute image area by inputting an image at every block, calculating the beature quantity of the block by performing an orthogonal transformation, deciding an image state of a notice block, and correcting the image state from a processing of its adjacent block. CONSTITUTION:A picture element density signal in an document image data which has been inputted is brought to A/D conversion by an A/D converter 11. The obtained data is corrected by a shading correcting circuit 12 by considering the uneven sensitivity, etc. of a CCD sensor. The data which is corrected is stored in a line buffer 13, and the data of a 4-line portion is sent successively to a Hadamard converting circuit 4. As a result, the intensity of a sequence which a picture element group in the block is extracted. This value is inputted to an edge quantity calculating circuit 15 and strength of the edge is calculated, and it is classified into areas of a character edge, a network point edge, etc. by an edge deciding circuit 16. In a correcting circuit 17, said decision is corrected in accordance with a kind of the edge of the blocks before and after a notice block. Accordingly, an erroneous decision is reduced. |
