Method of compressing data

摘要

Disclosed is a method for compressing data which is derived by tracing the contour line of a character pattern or a symbol. Normally such a contour line consists of at least one closed-loop line having straight portions and curved portions. A multiplicity of sampling points are selected along the contour line for the purpose of representing the contour line with these sampling points and those sampling points located along a straight or lightly curved portion of the contour line are disregarded and those located along a curved portion of the contour line are retained because the former have relatively less influence on the representation of the original character or symbol pattern than the latter. The determination of the significance of each sampling point is typically made by comparing the product of the length of a line segment connecting the sampling point of interest with the preceding sampling point and the angle defined by this line segment and another line segment defined by the sampling point of interest with the following sampling point.