Transmitting two television signals through one channel
First Claim
1. Apparatus for the transmission of two independent television signals through a transmission system designed for the transmission of a single television signal, comprising:
- a. first compression means for compressing the width of a first independent television image to produce an image of a first width being less than the width of the image supplied as input to said first compression means and greater than one-half of the width of said image supplied as input to said first compression means,b. second compression means for compressing the width of a second independent television image to produce an image of a second width being less than half of the width of the image supplied as input to said second compression means, the sum of said first width and said second width being within the maximum width of image capable of being transmitted by said transmission system designed for the transmission of a single television image,c. combining means for combining said image of a first width and said image of a second width to form a combined image, said combining means including means for horizontally positioning said image of a first width and separate means for horizontally positioning said image of a second width to be separated from, and horizontally adjacent to, said image of a first width,d. means for separating said image of a first width and said image of a second width from said combined image,e. first expansion means for expanding the width of said image of a first width to produce a first expanded image of normal width, andf. second expansion means for expanding the width of said image of a second width to produce a second expanded image of normal width.
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Accused Products
Abstract
Two input pictures are each compressed horizontally, one to three-quarters width, the other to one-quarter width, and combined side-by-side to form a single picture suitable for transmission over a standard link. The two signals are interchanged on alternate fields. Bandwidth limiting in the transmission link results in the signal compressed to one-quarter width having a final bandwidth one-third that of the other signal. This applies to each picture on alternate fields. A one-field delay repeats the high-frequencies from the field having wider bandwidth on the subsequent field, so that fine detail will be present on both fields. Lower bandwidth information is separately transmitted every field preserving vertical detail and the reproduction of motion at field rate. At the receiving end, the pictures are separated and expanded to normal width.
132 Citations
4 Claims
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1. Apparatus for the transmission of two independent television signals through a transmission system designed for the transmission of a single television signal, comprising:
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a. first compression means for compressing the width of a first independent television image to produce an image of a first width being less than the width of the image supplied as input to said first compression means and greater than one-half of the width of said image supplied as input to said first compression means, b. second compression means for compressing the width of a second independent television image to produce an image of a second width being less than half of the width of the image supplied as input to said second compression means, the sum of said first width and said second width being within the maximum width of image capable of being transmitted by said transmission system designed for the transmission of a single television image, c. combining means for combining said image of a first width and said image of a second width to form a combined image, said combining means including means for horizontally positioning said image of a first width and separate means for horizontally positioning said image of a second width to be separated from, and horizontally adjacent to, said image of a first width, d. means for separating said image of a first width and said image of a second width from said combined image, e. first expansion means for expanding the width of said image of a first width to produce a first expanded image of normal width, and f. second expansion means for expanding the width of said image of a second width to produce a second expanded image of normal width. - View Dependent Claims (2, 3, 4)
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Specification