Abstract: This invention relates to an improvement matching algorithm for analysing an X-ray images including an adaptive wavelet function as a linear combination of basic circular wavelet function which is an optimal wavelet function using dilations and shift of circular wavelets as building blocks. The resulting algorithm sequentially selects the most significant coefficient as one term on the linear combination that approximates the object. The matching results satisfy properties of rotation invariance, enabling match using only one angle view. The matched wavelet for other views can be quickly obtained by simply rotating the one matched result to the right angle.