Chain Codes Below Pixel Resolution
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Chain codes constitute a means for defining the edge shape of an object standing out against a contrasting background (as is known from numerous publications). The known methods of generating chain codes use an adaptable or a fixed threshold for edge scanning. The result (the chain code) defines the edge shape. (Image Omitted) As the pixels (picture elements) are resolved in four different directions (8 directions being also conceivable, since each pixel has 8 adjacent pixels), the resultant chain reflects the actual edge shape only approximately. This approximation relative to the size of the object is the better; the finer the resolution of an object is represented in the image store. The absolute approximation, however, does not exceed half the pixel length. Thus, the maximum error of the chain code is 0.