Patent ID: 7336842

Claim:
A method for generating data representative of characteristics of an image comprising: (a) inputting a plurality of face images; (b) transforming each of the face images into a two-dimensional discrete cosine transform (DCT) to obtain DCT coefficients, wherein each of the DCT coefficients includes DCT amplitude and DCT sign; (c) determining a plurality of average DCT amplitudes by averaging DCT amplitudes corresponding to each position of the DCT coefficients; (d) identifying average DCT amplitudes having at least a predetermined value and positions corresponding to the identified average DCT amplitudes; (e) storing positional information corresponding to the identified average DCT amplitudes; (f) inputting a first face image at an image input part; (g) transforming the first face image into a two-dimensional DCT at a DCT conversion part to obtain DCT coefficients, wherein each of the DCT coefficients includes DCT amplitude and DCT sign; (h) extracting the DCT signs from the DCT coefficients for the first image based on the stored positional information; and (i) generating a one-dimensional binary signal representation of the first face image based on the extracted DCT signs.