Sequential polygon approximation apparatus for contour and method thereof

摘要

A sequential polygon approximation apparatus for a contour and a method thereof which are capable of sequentially extracting a vertex in the order of a contour pixel when performing a polygon approximation so as to code a shape information, which includes an error computation unit for obtaining a contour pixel between two contour pixels of the vertex extraction unit from the contour pixel memory and computing an error which is a distance between a straight line between two contour pixels and a pixel from the contour pixel memory, a comparison unit for comparing an error obtained by the error computation unit with a threshold value, and a controller for controlling the vertex extraction unit and the error computation unit in accordance with the comparison result of the comparison unit, setting the pixel just before the final pixel of a first region as a first vertex when the error obtained in the first region which is the region of the contour pixel sequentially determined for the vertex extraction from a fixed one vertex is greater than a given threshold value, outputting the final pixel of a second region as a final vertex when all the errors obtained in the second region which is expanded till a predetermined contour pixel from the first region is smaller than the given threshold value, and outputting the first vertex as the final vertex.