Showing papers by "Charles R. Dyer published in 1984"

An analysis of node linking in overlapped pyramids

Abstract: An image segmentation algorithm is described that uses an overlapped pyramid to represent an image at multiple levels of resolution. The procedure `lifts' objects to levels of lower and lower resolution until they become `spot' or `streaklike' and are identifiable by local processing (using 3 by 3 operators). They are then `rooted.' The result is a forest embedded within the pyramid, with the single tree rooted at the pyramid apex representing the background regions and the remaining trees representing compact object regions. In addition to the definition of the pyramid linking algorithm, the convergence of the algorithm is proved and optimal rooting rules for binary images are analyzed.

Curve Detection in VLSI

Abstract: Four VLSI designs for a line and curve detection chip are presented. Each method is based on Montanari’s dynamic programming algorithm [9.1]. The output of each system is the sequence of coordinates or chain code of the optimal curve(s) detected. One method uses a systolic array of size proportional to the number of rows in the image to detect the optimal curve. To detect a curve of length m requires m passes through the systolic array, taking time proportional to m times the number of columns in the image. A second systolic array design consists of a linearly tapering pipeline of cells. The length of the pipeline is equal to m and the total number of cells in the pipeline is proportional to m3. Time proportional to the image area is required during a single pass through the image. The third systolic approach uses an array of cells of size proportional to m times the number of rows in the image. Only one pass through the image is required to detect the curve, taking time proportional to the number of image columns. Details are given for a VLSI chip design using the third approach. The fourth method describes an algorithm for an SIMD array machine.