| 摘要 |
PURPOSE: To improve the precision of edge detection by calculating the edge intensity to detect the picture element group, where the picture element value is steeply changed in comparison with peripheral picture element values, as an edge. CONSTITUTION: A gradient calculation part 11 to which an input picture Fin is supplied, a spline curve generation part 12 to which an outline P of contours is supplied, a parameter coordicate generation part 13 which generates a parameter (t) to the spline,curve generation part 12, and an edge intensity calculation part 14 which calculates an edge intensity E in accordance with the output from the gradient calculation part 11 and that from the spline curve generation part 12 are provided. The edge direction of each position in input picture data consisting of variable density data is estimated. The gradient in each position is obtained. The edge intensity calculation part 14 takes information of the estimated edge direction as auxiliary information and calculates the edge intensity E in accordance with this auxiliary information and the gradient, and the picture element group where the picture element value is steeply changed in comparison with peripheral picture element values is detected as an edge. |
