| 摘要 |
PURPOSE:To surely discriminate a character line picture area from a halftone picture area by checking whether or not a sudden change of density is recognized in the range of the input picture element data and its peripheral picture element data groups and furthermore whether the sudden changes of density are continuous in the specified direction or not. CONSTITUTION:The digital picture signals are delayed by the line memories 102 and 103 at a density changing point detecting part 100. Then 3 lines are inputted to a detecting circuit 104 at one time. The circuit 104 fetches the density data for each (3 X 3)-picture element block in the data equivalent to 3 lines and outputs the density data as the density change information. Each density change information is fetched by a deciding part 101, and the deciding result showing whether a noted picture element is equal to an edge part or not is outputted. In other words, it is decided whether the periphery of the noted picture element is included in an edge part of a binary picture or not based on the continuity of the density change directions as well as the density change of the input picture element. As a result, a character line picture area is surely discriminated from a halftone picture area. |
