Fast polygon scan conversion with medical applications

Abstract

The algorithm presented for polygon scan conversion is very fast and can replace the standard version in any application. Special requirements from medical data sets illustrate its practicality and versatility. The polygon scan conversion problem refers to filling the interior of a region represented by one or more polygons. The polygons are represented by the coordinates of their vertices in cyclic order. This problem shows up in many areas of computer graphics. The standard approach to polygon scan conversion creates two data structures, an edge table and an active edge table (AET). The edge table contains a bucket for each scan line. Each bucket consists of a linked list containing all the edges starting on that scan line (or straddling it for the first time). Creation of the edge table is an image-space step, since it depends on the number of scan lines existing in image space (that is, on the resolution of the target display device). In this respect, it is a device-dependent step. The algorithm we develop uses only an object-space data structure instead of the edge table and is therefore less device dependent. In particular, it is suitable for both raster and vector graphics devices.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>