Abstract: In a system for visual telecommunications, e.g. for use by deaf people, an electronic camera (20) makes an image of a moving subject for transmission. The TV type image is passed through a contour extractor (25) to be converted to an animated cartoon line-drawing type image. The contour image is then compressed by means including a sampler (28) for image reduction, a difference detector (30) for selecting only points which change from one image to the next, a filter (34) for rejecting isolated points in the contour image, and an encoder (36) for converting sequences of on/off bits into data words for transmission, via a modem (14) over a telephone line (15). At the other end of the line a similar transmitter/receiver system decodes the received words and reconstitutes the successive images for display on a screen (46).

Abstract: An improved method and apparatus for digital image processing is disclosed which permits greater efficiency in implementation of digital filtering techniques. In one implementation specially selected small generating kernels, or masks, are sequentially convolved with a data array of pixels representative of a particular image for more efficient restoration, enhancement or other conventional digital image processing techniques. The small generating kernels may be varied for each sequential convolution. In some implementations the output of each sequential convolution may be weighted in accordance with the filtering desired. Means for implementing the method are also disclosed.