Abstract: An image coding apparatus and method are disclosed. The method and apparatus are applicable to coding any array of arbitrary dimension. The apparatus utilizes FIR filters which generate three or more sets of coefficients from linear arrays generated from the array being coded. Each set of coefficients represents spatial frequency information of different frequencies. The filters utilize coefficient sets which are preferrably orthogonal.

Abstract: An apparatus for computing the discrete Fourier transform of a linear array variable f(j) of length N or of a planar array variable f(j,k) of dimensions N.times.M, wherein both N and M are even positive integers. The computation is divided into three parts, each suitable for computation via a multiprocessor array. Firstly, each element of the linear array f(j) is multiplied by the corresponding element of a first array constant. The resultant array is circularly convolved with a second array constant in the second step. The circular convolution may be computed in a straight forward manner or the second array constant may be resolved into N-1 simple array constants which are successively convolved. Lastly, each element of the resultant array after convolution is multiplied by the corresponding element of a third array constant. The invention is applied to a planar array by loading the planar array f(j,k) into corresponding elements of a planar array of processor elements.

Abstract: A system comprising apparatuses and methods for encoding and decoding spread spectrum signals is disclosed. Signals are encoded by modulating numerical sequences selected from an orthonormal basis of numerical sequences to provide channel coding. The modulated sequences are then combined to form an encoded signal. Because of the orthonormal character of the sequences, the encoded signal may be easily decoded using a matched filter. A method for generating long sequences from the product of shorter sequences is also disclosed.

Abstract: A system for compressing images is disclosed. The system utilizes a transformation which is equivalent to expanding the image using a system of wavelets having finite support.

Abstract: A modular digital signal processor system for calculating "wavelet-analysis transformations" and "wavelet-synthesis transformations" of one-dimensional numerical data and multi-dimensional numerical data for solving speech processing and other problems. The system includes one or more "dual-convolver" components, "analyzer-adjunct" components, "synthesizer-adjunct" components, "de-interleaver components" and "interleaver components", and specific configurations of these components for implementing specific functions. Each dual-convolver is capable of loading a finite number of numerical values into its coefficient registers and subsequently performing two convolution operations on input sequences of numerical values to produce an output sequence of numerical values. Two dual-convolvers are configured with an analyzer adjunct or synthesizer adjunct to respectively build a single stage analyzer or synthesizer.

Abstract: A multiple mirror reflective surface for use in a multiple mirror telescope in which the objective surface of telescope is tiled with substantially identical planar mirrors having irregular boundaries and a mirror for use therein. The mirrors are groupable into groups of seven, one of which is bounded symmetrically by the other six, each mirror having an approximately fractal peripheral boundary such that each group of seven mirrors has a boundary shape which is approximately geometrically similar to that of the mirrors forming the group. The mirrors of such an array have their centers on a hexagonal lattice of points in the objective surface. In a particular embodiment, the mirrors have shapes which approximate that of a fractal shaped mirror by being defined by a combination of hexagonal shapes. With mirrors of this shape, the multiple mirror telescope experiences less optical aberrations which would otherwise be caused by linear edges of the mirrors, without reducing light gathering power.