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.