Rapid search for spherical objects in aerial photographs

A methodology is presented for designing detectors which locate specific features in an image. The method is applied to the detection and segmentation of spherical features. A vital part of the detection and segmentation is the use of the gradient angle transform. An analysis of the gradient angle for ideal spheres is presented, with a discussion of how this may be used to locate the boundaries of the sphere. The algorithms used by a program which detects and segments spherical features are then presented. The results of applying the program to images with man-made spherical features are given.<<ETX>>

[1]  John M. Prager,et al.  Extracting and Labeling Boundary Segments in Natural Scenes , 1980, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[2]  Dana H. Ballard,et al.  Computer Vision , 1982 .

[3]  Bir Bhanu,et al.  Segmentation of natural scenes , 1987, Pattern Recognit..

[4]  Richard O. Duda,et al.  Use of the Hough transformation to detect lines and curves in pictures , 1972, CACM.

[5]  Manfred H. Hueckel.  A Local Visual Operator Which Recognizes Edges and Lines , 1973, JACM.

[6]  Azriel Rosenfeld,et al.  Scene analysis using region-based constraint filtering , 1984, Pattern Recognit..

[7]  R A Kirsch,et al.  Computer determination of the constituent structure of biological images. , 1971, Computers and biomedical research, an international journal.