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EP0486468A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Processing circuit for video signals

Assignee: Grass Valley Group Inc
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Filing: 1987-03-05
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Granted: —
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Expires: 2007-03-05
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Abstract

Abstract A first shaped video signal V₁K₁ and a second shaped video signal V₂K₂, are combined so as to generate a third shaped video signal V₃' given by V₃' = V₁ K₁ [1 - K₂(1 - P₁₂)] + V₂K₂(1 - K₁P₁₂) where P₁₂ is a priority signal. A key signal K₃ given by K₃ = 1 - (1 - K₁)(1 - K₂) is also generated. An output processor receives the shaped video signal V₃', the key signal K₃ and a matte signal M₃. In a first mode of operation, the output video signal V₃'' of the output processor is given by V₃'' = V₃ + M₃(1 - K₃) and the key signal K₃' that is generated by the output processor has a constant value, and in a second mode of operation of the output processor the output video signal is given by V₃'' = V₃'/K₃ and the key signal K₃' is directly proportional to K₃.

Inventors

  • 👤 Richard A. Jackson
  • 👤 Kevin D. Windrem

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 11:52
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/222; H04N5/262; H04N5/272; H04N5/265; H04N5/275

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 106 words
A processing circuit for receiving a shaped video signal V₃' and an associated key signal K₃ and providing output signals in response thereto, said processing circuit having at least a first mode of operation and comprising first means operative in the first mode of the processing circuit to generate from the shaped video signal V₃'' and the associated key signal K₃ an output video signal V₃'' given by V₃'' = V₃' + A where A is a function of the associated key signal and is independent of V₃', and second means operative in the first mode to generate an output key signal having a constant value.
Claim 2
Dependent Claim 67 words
A processing circuit according to claim 1, having a second mode of operation, and wherein the first means are operative in the second mode to generate an output video signal V₃'' given by V₃'' = C V₃'/K₃ where C is a constant, and the second means are operative in the second mode to generate an output key signal that is directly proportional to the key signal K₃.
Claim 3
Dependent Claim 46 words
A processing circuit according to claim 1, wherein the output processor has an input terminal for receiving a matte signal M₃ and is operative in the first mode to generate an output video signal V₃'' given by V₃'' = V₃' + M₃(1 - K 3) .

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