| 摘要 |
PURPOSE:To perform sure quantization by setting quantization slice levels in accordance with the read signals corresponding to the specific area on an object to be read out of the read signals to be clamped. CONSTITUTION:A read part 1 along the conveyance direction (a) of postal matter P to be conveyed is provided, and the postal matter P is optically read and scanned with an irradiation lamp 2, an imaging lens 3 and an image pickup device 4. A line array 4 which is the image pickup device is of the self-scanning type wherein plural pieces of solid-state image sensing elements are arranged. It is so arranged that when the postal matter P corresponds to the part 1, the matter P is linearly scanned in the direction intersecting orthogonally with the conveyance direction (a), and the linear scanning thereof is moved successively in the direction opposite apparently to the conveyance direction (a) by the movement of the postal matter P, and the signal of the level corresponding to the state of the plane of the figure of the postal matter P is outputted from the array 4. Further, the read signal of the part 1, that is, the output signal of the array 4 is converted to the level optimum for the quantization processing of the post stage and is outputted through a signal processing circuit 10. |
