Analog gaussian convolver

Abstract

An analog Gaussian convolver for performing high speed convolutions of arrary functions (e.g. image arrays) with masks or operators which uses two units of 2-dimensional Gaussians G(u,v) and the like. The output of the two units are subtracted to obtain difference of Gaussian operators (DOG), a very important parameter in computer vision. Input data in the form of a 2-dimensional digital array representing image pixels from the image array is converted into analog form and is then convolved with a 1-dimensional Gaussian operator in a first direction and the result is clocked into a tapped analog delay line. The outputs of the analog tapped delay line are also convolved with another (normally identical) 1-dimensional Gaussian operator in a direction normal to the first direction. The results so obtained represents the convolution of the image with a 2-dimensional Gaussian operator in a channel. By duplicating the two 1-dimensional convolvers and driving a second channel with the same rastering window, the image can be simultaneously convolved with another Gaussian operator and obtaining convolution with a DOG which is useful in a computer vision system for edge detection and binocular stereo.