Abstract: The invention relates to a computed tomography method in which a conical radiation beam traverses an examination zone during a helical relative motion between the radiation beam and the examination zone. The reconstruction is performed by means of filtered backprojection, the filtering operations involving measured values resulting from different projections of voxels from at least approximately the same surface within the examination zone.

Abstract: The invention relates to a computed tomography method in which the summing operation required for filtered backprojection is performed in two steps, filtering being performed only after the first summing step. This method is preferably performed for the points on a surface, which is defined by parallel rays, which are situated in parallel planes and link oppositely situated segments of the helix.

Abstract: The invention relates to a computed tomography method in which the summing operation required for filtered backprojection is performed in two steps, filtering being performed only after the first summing step. This method is preferably performed for the points on a surface, which is defined by parallel rays, which are situated in parallel planes and link oppositely situated segments of the helix.

Abstract: The invention relates to a CT method which involves helical scanning of an examination zone by means of a cone beam. Measuring data for the three-dimensional tomographic imaging of objects of arbitrary length are now acquired completely and without redundancy. The reconstruction requires only a one-dimensional filtering operation. Particularly simple processing steps are enabled by a rebinning operation during which fan beams which are situated in planes extending parallel to one another and to the axis of rotation are combined.

Abstract: Complete helical cone-beam scanning and non-redundant data acquisition are obtained for three-dimensional tomographic imaging of arbitrary long objects. The minimum sized two-dimensional detector window is bounded by two consecutive turns of the helix. The ray source exposes all object points during a rotation of exactly 180 degrees when seen from the points themselves. Only one-dimensional filtering is employed in the reconstruction. Rebinning to parallel beams, as seen along the axis of rotation, allows for especially simple procedures without any need for pre-weighting or magnification factors. As a special case, the invention is applicable to helical fan-beam scanning with one-dimensional detector arrays.

Abstract: Configured for accelerated operation of processing elements in a SIMD parallel processing system is disclosed. The output of an exclusive-OR gate is coupled to one input of the element ALU while a first input of the gate is adapted to receive signals intended for the ALU input. Upon loading a `1` bit into a register coupled to a gate second input, signals applied to the gate first input are complemented and applied to the ALU input. As a result, different arithmetic and logic operations can be performed simultaneously by different elements in the processing system in response to a single series of instructions.

Abstract: A device examines a two dimensional quantized picture to determine whether any objects are closer together than a set minimum distance. The quantized picture has incremental areas assigned values of 0 or 1 corresponding to the presence or absence of an object. An array of interconnected logical cells identifies the presence of a separate object in the picture. The dimensions of the array correspond to the acceptable minimum distance between objects.The device may be used to inspect for insufficient conductor separation or unacceptably wide conductors in printed circuit boards.

Abstract: A device for the examination of distances between two spaced apart objects in a two-dimensional digitized picture. A logical unit senses the binary values of the elements of a test pattern. Based on certain transitions in the values of the test pattern elements, the unit determines whether the distance between the two objects is less than a smallest allowable distance. A warning signal is generated if the objects are closer than the smallest allowable distance.