1. A method for automatic arrangement determination of partial radiation images for reconstructing a stitched full image comprising: acquiring at least two radiation sub-images of an elongated object by means of corresponding overlapped radiation recording media; converting said recorded sub-images to digital images and storing them; constructing a hypothesis list that includes all possible yet unique arrangements of sub-image order, orientation and overlap; detecting overlap regions for each consecutive sub-images pair in each hypothesis; conducting a plurality of different measurements on every consecutive sub-image pair of each hypothesis and deleting the hypothesis from the list if any measurement result is out of range; calculating the correlation function of the overlap regions for each consecutive sub-image pair in each hypothesis left in said hypothesis list and finding the function maximum and the horizontal displacement between the sub-image pair; checking the magnitude of the horizontal displacement between each consecutive sub-image pair and rejecting the hypothesis from the hypothesis list if the magnitude is out of range; establishing an overall figure-of-merit for each hypothesis left in the hypothesis list based on the sum of the maximum of the correlation functions; selecting the hypothesis of maximum figure-of-merit for best candidate; and processing the sub-images based on selected hypothesis for stitching to produce an output image consisting of the stitched sub-images.