| 摘要 |
PURPOSE:To improve a picture quality by removing a noise, shading, and density nonuniformity of a background included in a picture while holding the edge of the picture. CONSTITUTION:The density of the first picture element of each scanning line of one picture signal from a photographing device is stored by a hold circuit 1, and the picture signal is delayed for the picture elements by a delay circuit 2. The signal outputted from the circuit 2, and the original picture signal are transmitted to a subtracting circuit 3, and the picture signal delayed for one picture elements is subtracted from the original signal, so that a prescribed contrast picture can be obtained. At that time, the contrast picture is transmitted to a threshold circuit 4, and 0 is outputted when the absolute value of the contrast is less than a certain value, and the original values are outputted when the absolute value of the contrast is more than a certain value, so that the noise, shading, and the density nonuniformity of the background can be removed. The signal outputted from the circuit 4 is inputted to an integration circuit 5, and integrated by using the density signal of the first picture element of each scanning line from the circuit 1 as an initial value, so that a picture signal whose picture quality is improved can be outputted. |
