A wavelet-based technique for image similarity estimation

In this paper we proposed a method to evaluate the similarity of images compressed by a given digital wavelet transform, which allows for comparing lossless or lossy-compressed images. Two features that describe the image structural content, edge point locations and edge density, are computed directly from multiscale data. Depending on the image type and the feature selections for processing, the distance between two images is computed in one- or two-dimensional space. This method facilitates content-based image querying and automatic database retrieval. In addition, images can be sorted and appropriately indexed with respect to such global characteristics as smoothness, texture direction and repetition period.