Method and apparatus for visual telecommunications, in particular for use by the deaf
First Claim
1. In an apparatus for generating signals in real time representative of visual information, in particular visual information relating to movements of the human body, the apparatus being of the type comprising:
- a camera suitable for forming successive images and for converting each such image into a sequence of corresponding electrical signals;
binary conversion means for converting the signal representative of each point in the sequence into binary form; and
encoding means for encoding the resulting sequences of binary signals, the improvement which includes means for compressing said signals to a data rate compatible with transmission over an ordinary telephone line by virtue of said binary conversion means which link the camera to the encoding means, said means for compressing comprising means responsive to changes in brightness between neighboring points within each image to extract contours present in the original image, said binary signals then being representative of said extracted contours.
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Accused Products
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). The resulting animated cartoon type of display is adequate for communication by sign language or by lip reading, and is capable of being sufficiently compressed to be transmitted over a normal telephone line.
75 Citations
19 Claims
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1. In an apparatus for generating signals in real time representative of visual information, in particular visual information relating to movements of the human body, the apparatus being of the type comprising:
- a camera suitable for forming successive images and for converting each such image into a sequence of corresponding electrical signals;
binary conversion means for converting the signal representative of each point in the sequence into binary form; and
encoding means for encoding the resulting sequences of binary signals, the improvement which includes means for compressing said signals to a data rate compatible with transmission over an ordinary telephone line by virtue of said binary conversion means which link the camera to the encoding means, said means for compressing comprising means responsive to changes in brightness between neighboring points within each image to extract contours present in the original image, said binary signals then being representative of said extracted contours. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- a camera suitable for forming successive images and for converting each such image into a sequence of corresponding electrical signals;
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13. A method for transmitting information based on movements of the human body, between a first and a second station, remote from each other, said method comprising the steps of:
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(a) acquiring at said first station video signals representing successive images of said human body; (b) converting said video signals into first digital signals, each corresponding to a point in one of said successive images; (c) processing said digitial siganls, within each image, to determine for each point of the image, a binary signal indicating whether that point belongs to a contour of said image; (d) encoding such binary signals indicating a contour point into second digital signals; (e) transmitting said second digital signals to said second station through a telecommunication network; (f) receiving said second digital signals at said second station; (g) reconstituting the contours of the successive images, at said second station, from said second digital signals, and (h) displaying the contour images at the second station. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification