In a crushing system, an interlocked operation of operation units including a grizzly feeder, a crusher and a delivery conveyor and so on is stopped by depressing an interlock OFF switch. Image data is obtained from an image detector and a look-up table is generated for image data processing, wherein the look-up table is generated at least according to information about an image type, an image detector type, and a kVp setting used to expose the radiographic image and according to information about grid use. By precomputing coefficients for the nodes in the mesh, it is possible for a single set of equations to support plane waves, point sources, PML ABCs, and PEC walls.