1. A method for retrieving an image texture descriptor for describing texture features of an image, comprising the steps of: (a) filtering input images using predetermined filters having different orientation coefficients; (b) projecting the filtered images onto axes of each predetermined direction to obtain data groups consisting of averages of each directional pixel values; (c) selecting candidate data groups among the data groups by a predetermined classification method; (d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups; and (e) determining the plurality of indicators as the texture descriptor of the image.