| 摘要 |
PURPOSE:To ensure the original information of a digital signal by deciding correctly whether a picture element is valid or invalid, even for the high frequency band of such picture images as a tine line and a contour line by observing the change of picture element correlation. CONSTITUTION:For every picture element belonging to a picture system, a correlation operation circuit 23 outputs plural correlative vectors, whose correlation intensity about the correlation directions of N directions (N>=2) on a two dimensional space is expressed by an N-nominal combination for the objective picture element and its vicinity picture element. A validity deciding means 21 decides the true validity or invalidity of the picture element, decided to be invalid by an error flag, according to the existence of the correlation of the plural correlative vectors. Separately from this, an operation circuit calculates the retouched value of the objective picture element, and the substitution of the former value and the retouched value of the objective picture element, which is decided to be invalid by the error flag and besides, decided to be of the true invalidity by the validity deciding means 21, is executed by a substituting means 31. |
