Abstract: A recursive Radon video transform processor, for detecting signal responses from objects to be recognized, generates a special manifold of the response data for Radon transformation of the stored data before operation thereon by a subsequent enhancement process, prior to display or other utilization. Each Cartesian data point contributes to multiple Radon transforms, so that the recursive Radon transform video implementation only processes the newest and oldest lines of data to update the transform for a given sliding window in the data manifold. For a data line of fixed length .rho., and with each of a set of N separate angular subprocessors operating, the pixel X value of the first and the last data rows are offset by a window size (w=x* tan .theta..sub.i), where .theta..sub.i is the transform angle for a particular subprocessor, as determined by a desired resolution, so that window size variations are implemented by a programmable change in time delay.

Abstract: Image data is subjected to a thinning process so as to derive a medial axis for each image. Boolean image data is reduced to lines and/or dots, each line generally being a centroid line of an image. The thinning process uses a change look-up table which is addressed using values from pixels in the neighborhood of a particular pixel which is the target for possible change. Pixels in the neighborhood which are to be evaluated are given a weight by use of a weight look-up table and the weight of the pixel is multiplied by the value of the pixel. Alternately, the weight of the pixel may be added to the pixel value. The pixels in the neighborhood of a target pixel (i.e., pixel which is being evaluated for possible removal) have their weights and values taken into account by a summation of the results of the multiplication (or addition) performed for each pixel so as to provide an address used to address a change look-up table which supplies an output indicative of change in the target pixel.

Abstract: The medial axis representation of an image stored in an input memory is created in an output memory using only a moving 3-pixel by 3-pixel window to "view" the stored image. The medial axis contains no breaks.

Abstract: An array of Radon transform processors accepts signals representative of the x and y positions of each pixel of an image together with signals representative of the magnitude or brightness of the image. Each Radon transform processor of the array is associated with one value of .theta., an angle relative to the x-axis, and each processor is associated with a different .theta.. Each radon transform processor multiplies the current value of x by cos .theta. and the current value of y by sin .theta., and adds the products to produce the value of rho, the distance from the image center along a line at angle .theta., at which each pixel contributes to a line integral. A memory stores the current pixel's magnitude by updating the line integral associated with the current value of rho by adding the pixel magnitude. When all pixels of the image have been evaluated, the memory of each processor of the array is read in sequence, and the value of the line integral for each value of rho is read from each memory.

Abstract: A laser tube is rigidly mounted within a cylindrical metallic housing, and end rings are attached thereto. Each end ring has an opening for passage of the beam, and a plurality of radially disposed openings. Inside the housing, a smaller adjustment ring is provided, and outside the end rings are reference rings adapted to receive lenses, filters, or the like. Screws engage and penetrate the outer ring, pass freely through the end ring, and engage the inner ring. The outer and inner rings are movably adjustable relative to the housing axis and the laser beam, whereby optical apparatus attached to the outer ring may be positioned precisely relative to the laser beam.