RESEARCH ON WAVELET TRANSFORM IN SHAPE-BASED IMAGE RETRIEVAL

The key point for shape-based image retrieval is to detect and extract the object edge, i.e., get the object shape or outline of the image. In terms of the shape features, the feature vector of the shape can be generated, then, the similarity matching is carried out among the feature vectors. This paper presents the wavelet algorithm to extract the edge of the object from the image. Since each pixel of edge is of orientation, the orientation angle of pixel can be calculated in the range of 0∼2π and generate the histogram to describe the shape. As the feature vector, the histogram is used to the image matching retrieval.