| 摘要 |
PURPOSE:To discriminate a line drawing, a continuous gradation picture and a dot gradation picture by dividing a picture into blocks, dividing picture elements in each block into two groups having low and high density and forming a histogram having an effective density representing value of each group. CONSTITUTION:An original 1 is placed to a transparent original plate 2 and a light reflected onto the original 1 from a light source 3 and converged by a lens 5 is received by a photoelectric converting element 6. The original 1 is divided into some blocks and picture elements in each block are divided into two groups having higher and lower density than the average density of each block. Further, the type of the picture is identified as any of the line drawing, continuous gradation picture and dot gradation picture from the histogram for the difference of the density representing values of each groups. |
