Object Cues for Model-based Image Interpretation

This paper is concerned with generating object cues from grey-level images for use in model-based image interpretation. We describe the idea of local grey-level symmetry and illustrate how points in the grey-level image with this property form local axes of symmetry. These axes together with appropriate scale information form the object cues. The degree of local symmetry in the grey-level image is made explicit by introducing a Centre of Gravity filter. The local axes of symmetry are shown to appear in the centre of gravity image as troughs and a method for labelling the troughs is described. We give results for real images and make an objective comparison with other published methods.