Two Compact Codes for Rectangular Drawings with Degree Four Vertices

Abstract

A rectangular drawing is a partition of a rectangle into a set of rectangles. Rectangular drawings have many important applications including VLSI layout. Since the size of rectangular drawings may be huge, compact encodings are desired. Several compact encodings of rectangular drawings without degree four vertices are known. In this paper, we design two compact encodings for rectangular drawings with degree four vertices. We give 5f - B - n₄ bits and 5f - B - W - 3 bits encodings for rectangular drawings, where f is the number of inner faces, n₄ is the number of vertices with degree four, and B (resp. W) is the number of inner faces touching the bottommost horizontal (resp. rightmost vertical) line segments.