Abstract: A method of operating a computing machine for reducing speckle noise in video images, particularly radar images, utilizes a complementary hulling technique on vertical pixel grids of the array. The vertical pixel contours which are subjected to the complementary hulling are derived from intersections of vertical grids with conceptual superposed gray-scale surfaces which have front end values corresponding to the gray-scale pixel values. The invention provides the significant advantages of decaying small image features, such as speckle noise at a significantly faster rate than large image features, such as target returns.

Abstract: A method and apparatus are disclosed for determining whether a shape or pattern exists anywhere in a particular image represented by a matrix of digital data signals. In the preferred embodiment, a suitably programmed general purpose computer provides means for storing the matrix of data signals representing the first image, computing the complement of the first image matrix and storing the complement image matrix, creating a structuring element representative of the target shape to be recognized and storing a matrix of digital data signals representing that structuring element, and creating a second structuring element equal to the window complement of the first structuring element and storing the second structuring element.

Abstract: A method of automatically recognizing objects in a digital image. The pixel coordinates of the boundary of the objects are identified and stored as data. A series of Fourier coefficients describing the boundary of the object are calculated and used to generate a set of descriptors. The descriptors are stored and compared with similarly generated descriptors of other objects to determine correspondence therebetween.