| 摘要 |
PURPOSE:To discriminate a picture whether it is a line drawing or a gradation picture depending on the distribution of the 1st density threshold value and to discriminate the picture whether or not it is the gradation picture having a broad density region depending on the distribution of a density signal to the 2nd density threshold value being higher than that of the 1st density threshold value. CONSTITUTION:Photoelectric conversion is done at a processing (1) from a luminous amount signal So into an electric picture signal Se at each spot having >=0.01mm.<2> of area, and the picture signal Se is sampled at a processing (2). The Se being an analog quantity is A-D-converted at a processing (3), the digitized picture signal Se is counted at a processing 4 for the formation of a histogram. The formed histogram is shared to a high or a low density region at a processing 5 depending on the 1st and the 2nd density threshold value, e.g., density 0.4 and 0.8 respectively, and the accumulated value is obtained. |
