Edge Detection and Ridge Detection with Automatic Scale Selection

When computing descriptors of image data, the type of information that can be extracted may be strongly dependent on the scales at which the image operators are applied. This article presents a systematic methodology for addressing this problem. A mechanism is presented for automatic selection of scale levels when detecting one-dimensional image features, such as edges and ridges. A novel concept of a scale-space edge is introduced, defined as a connected set of points in scale-space at which: (i) the gradient magnitude assumes a local maximum in the gradient direction, and (ii) a normalized measure of the strength of the edge response is locally maximal over scales. An important consequence of this definition is that it allows the scale levels to vary along the edge. Two specific measures of edge strength are analysed in detail, the gradient magnitude and a differential expression derived from the third-order derivative in the gradient direction. For a certain way of normalizing thes...

• Type: Conference
• Year: 1996
• Where: CVPR
• Authors: Tony Lindeberg
• Keywords: Computer Vision, CVPR 1996, Edge Detector, Edge Response, Edge Strength, Scale-space Edge, Scale-space Smoothing