Image reconstruction using divergent beams distributed over limited angle

We present a new image reconstruction technique from acquisition data in divergent geometry distributed over a limited angle. In many practical situations, it is not possible to obtain the data distributed over the whole 360/spl deg/. For example, when the test object presents anisotropic properties, i.e., when it is extremely sensible to the radiation coming from some specific direction. Physical constraints can also obstruct the acquisition of data in all angles. The proposed technique solves this problem by allowing image reconstruction from data distributed over a limited angle. This technique first converts the divergent projections distributed over a limited angle into parallel projections homogeneously distributed over the whole contour of the test object. Then, an algorithm based on extended entropy reconstructs the image.