1. A method for retrieving a corresponding video sequence having a set of image frames of digital video data from a database in response to a query video sequence, the method comprising the steps of: a) calculating, by a computer, L representative edge histograms of the query video sequence as an image descriptor for the query video sequence, wherein each representative edge histogram represents a representative spatial distribution of 5 reference edges in sub-images of image frames in the query video sequence, wherein the reference edges includes 4 directional edges and a non-directional edge; b) extracting, by the computer, a plurality of image descriptors for video sequences based on digital video data information from the database, wherein each image descriptor for said each video sequence includes L representative edge histogram bins for said each video sequence; c) comparing, by the computer, the image descriptor for the query video sequence to said each image descriptor for each video sequences to generate a comparison result, the comparison result indicating a degree of similarity between the query video sequence and the video sequences; and d) retrieving, by the computer, at least one video sequence based on the comparison results, wherein the step b) includes the steps of: b1) retrieving L×5 quantization index values for each of the target video sequence; b2) converting each of the L×5 quantization index values into L×5 representative edge histogram bins for said each target video sequence by using 5 non-linear inverse quantization tables; and b3) generating L representative edge histograms based on the L×5 normalized edge histogram bins.