EP0512839A2
Expired / Lapsed
EP
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Image keying generator for video special effects
Assignee: Quantel Ltd
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Filing: 1992-05-08
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Granted: —
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Expires: 2012-05-08
Abstract
Abstract An image processing system operates on first and second image data (V and Bg) to produce data defining a combined image (R=V+Bg(1-α)). The first image data (V) represents a keyed image (V=FK+B/1-K)) comprising a first object (F) keyed over a portion of a first background (B) in accordance with keying data (K). The second image data (Bg) represents a background. The system is arranged so that the second image data (Bg) is weighted by respective control data (α) (fig.1B) related to said keying data (K) before being combined with the first image data (V). In another embodiment (fig.3) the first image data (V) represents a second object independently keyed over the keyed image in accordance with second keying data (K2) and the control data (α) is further related to the second keying data. In a further embodiment (fig.4) the first image data represents an image derived by cross fading between the first keyed image and a second keyed image.
Inventors
- 👤 Neil Roy Hinson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 05:00
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/222; H04N5/262; H04N5/272; G; G06; G06T; G06T11/00; G06T11/10; H04N5/275
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
103 words
An image processing system in which first image data, representing at least one foreground image keyed to a portion of a first background in accordance with respective keying data, is combined with second image data, representing a second background, to produce data defining a combined image comprising said at least one foreground image keyed to a portion of said second background, the system being arranged such that the second image data is weighted by control data derived from said keying data before being combined with the first image data such that data representing the first background is replaced by the second image data.
Claim 2
Dependent Claim
45 words
An image processing system as claimed in claim 1, wherein said first image data represents plural foreground images independently keyed to portions of said first background in accordance with respective plural keying data, and wherein said control data is derived from said plural keying data.
Claim 3
Dependent Claim
31 words
An image processing system as claimed in claim 1 or 2 wherein the control data is derived by operating with said keying data on data representing image white and image black.
Claim 4
Dependent Claim
18 words
An image processing system as claimed in any preceding claim, wherein said first background is a black matte.
Claim 5
Dependent Claim
21 words
An image processing system as claimed in any preceding claim, wherein said first and second image data are combined by addition.
Claim 6
Dependent Claim
32 words
An image processing system as claimed in any preceding claim, wherein said foreground and background images each comprise a plurality of picture elements and are combined on an element by element basis.
Claim 7
Dependent Claim
19 words
An image processing system as claimed in any preceding claim, wherein the combined image data is output for display.
Claim 8
Dependent Claim
80 words
A keying system for image processing, the system comprising: a source of first video signals V representing at least one foreground object F keyed over a first background B; a source of second video signals representing an arbitrary background Bg; a source of key signals (α) for keying the foreground object over the arbitrary background Bg; and a keying circuit responsive to said first and second video signals and said key signals to produce the result = V + Bg(1-α).
Claim 9
Dependent Claim
72 words
An image processing system comprising a first data source for supplying first image data representing a first image formed from at least one foreground image keyed to a first background image by interpolation in accordance with at least one respective first interpolation co-efficient and for supplying a second interpolation coefficient derived from the or each first interpolation coefficient, and a divider for dividing the first image data by the second interpolation co-efficient.
Claim 10
Dependent Claim
50 words
An image processing system as claimed in claim 9, further comprising a second data source for supplying second image data representing a second background image, and a keying circuit for keying said divided first image data and said second image data by interpolation in accordance with the second interpolation co-efficient.
Claim 11
Dependent Claim
20 words
An image processing system as claimed in claim 9 or 10, wherein said first background image is a black matte.
Claim 12
Dependent Claim
41 words
An image processing system as claimed in claim 9 or 10 or 11, wherein the second interpolation coefficient is derived by interpolating between signals representing image black and image white in accordance with the or each said respective first interpolation co-efficient.
Claim 13
Dependent Claim
41 words
An image processing system as claimed in any of claims 9 to 12, wherein the divider comprises a look-up table responsive to the first image data and said second interpolation coefficient for outputting data corresponding to said divided first image data.
Claim 14
Dependent Claim
40 words
An image processing system as claimed in any of claims 10 to 13, wherein said first and second images each comprise a plurality of picture elements and said first and second data are keyed on a element by element basis.
Claim 15
Dependent Claim
29 words
An image processing system as claimed in claim 14, wherein said at least one first and said second interpolation co-efficient are each defined on an element by element basis.
Claim 16
Independent Claim
68 words
A method of processing image data, the method comprising supplying first image data representing a first image formed from first image data representing at least one foreground image keyed to a first background image by interpolation in accordance with at least one respective first interpolation coefficient, deriving a second interpolation coefficient from the or each first interpolation coefficient, dividing the first image data by the second interpolation co-efficient.
Claim 17
Dependent Claim
38 words
A method as claimed in claim 16, further comprising obtaining second image data representing a second background image, and keying said divided first image data and said second data by interpolation in accordance with the second interpolation co-efficient.
Claim 18
Dependent Claim
27 words
A method as claimed in claim 16 or 17, wherein data in a look-up table is used to determine said divided first data from said first data.
References Cited (Backward Citations)
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