Patent EP0174700A1 successfully refreshed from Google Patents.
EP0174700A1
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Apparatus for processing video signals
Assignee: Koninklijke Philips NV
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Filing: 1985-09-10
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Granted: —
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Expires: 2005-09-10
Abstract
Abstract An arrangement for rotating television pictures comprises a frame store (10) into which a rotated input picture is written under the control of a write address generator (12) which is in turn controlled by a rotation control and timing generator (5). A video input signal is applied at input (1) and fed to a splitting circuit (4) which produces streams of even and odd numbered samples, both at the sampling rate. These streams of samples are fed to an interpolator (8) where they are used to generate samples to be written into the store (10). The store (10) is split into four areas which are arranged to hold respectively field 1 odd samples, field 1 even samples, field 2 odd samples, and field 2 even samples. The write address generator (12) is controlled so that samples from field 1 of the input signal are fed only into the areas of the store read by the read address generator (14) during field 1 of the output signal and samples from field 2 of the input signal are fed only into the areas of the store read by the read address generator (14) during field 2 of the output signal.
Inventors
- 👤 Anthony John Field
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 14:32
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/60; G06T3/606; H; H04; H04N; H04N5/00; H04N5/222; H04N5/262; H04N5/2628
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
365 words
Apparatus for processing input video signals having the form of digitally encoded samples and being arranged so that successive samples produce a television picture on a display screen by line and field sequential scanning: the apparatus comprising a field store; a first address generator for generating a set of addresses for addressing memory locations in the field store, the set of addresses being generated from input signals defining a given geometrical modification of the input television picture represented by the input video signal samples; an interpolator for receiving said input video signals and producing interpolated samples in response to said input signals defining the given geometrical modification, said first address generator being effective to assign to each sample produced by the interpolator a memory location indicated by an address of said set of addresses; and a second address generator for generating addresses of at least a selected part of the field store to enable video signal samples to be read from the locations of the selected part of the field store to form a series of video signal samples which represent the modified television picture: characterised in that said apparatus further comprises a generator for producing, from the input video signal samples, samples which occur at twice the rate at which samples are written into the field store, and means for supplying the generated samples to the interpolator twice in each input line scanning period, that the field store comprises at least two parts, one part for storing odd numbered samples of each output video line of the field and the other part for storing even numbered samples of each output video line of the field; that said set of addresses generated by said first address generator comprises a first sub-set which assigns interpolated samples to the one part of the field store and a second sub-set which assigns interpolated samples to the other part of said field store; and that said apparatus still further comprises means for supplying to an output successive samples read from locations of the field store indicated by the second address generator such that successive samples at the output are derived alternately from the one part and the other part.
Claim 2
Dependent Claim
365 words
Apparatus for processing input video signals having the form of digitally encoded samples and being arranged so that successive samples produce a television picture on a display screen by line and field sequential scanning: the apparatus comprising a field store; a first address generator for generating a set of addresses for addressing memory locations in the field store, the set of addresses being generated from input signals defining a given geometrical modification of the input television picture represented by the input video signal samples; an interpolator for receiving said input video signals and producing interpolated samples in response to said input signals defining the given geometrical modification, said first address generator being effective to assign to each sample produced by the interpolator a memory location indicated by an address of said set of addresses; and a second address generator for generating addresses of at least a selected part of the field store to enable video signal samples to be read from the locations of the selected part of the field store to form a series of video signal samples which represent the modified television picture: characterised in that said apparatus further comprises a generator for producing, from the input video signal samples, samples which occur at twice the rate at which samples are written into the field store, and means for supplying the generated samples to the interpolator twice in each input line scanning period, that the field store comprises at least two parts, one part for storing odd numbered samples of each output video line of the field and the other part for storing even numbered samples of each output video line of the field; that said set of addresses generated by said first address generator comprises a first sub-set which assigns interpolated samples to the one part of the field store and a second sub-set which assigns interpolated samples to the other part of said field store; and that said apparatus still further comprises means for supplying to an output successive samples read from locations of the field store indicated by the second address generator such that successive samples at the output are derived alternately from the one part and the other part.
Claim 3
Dependent Claim
75 words
Apparatus as claimed in Claim 1, characterised in that said generator comprises a selection unit having an input for receiving said input video signal samples, a first output at which the odd numbered samples of each line are produced and a second output at which the even numbered samples of each line are produced, the samples at the first and second outputs being produced at the same rate as the samples applied to the input.
Claim 4
Dependent Claim
122 words
Apparatus as claimed in Claim 2, characterised in that said selection unit comprises first and second sample memories, address generation means for generating addresses for assigning input video signal samples to successive locations of the first and second memories, said address generation means being arranged to read out the odd numbered sample locations only from the first sample memory and the even numbered locations only from the second sample memory, said odd and even numbered locations being read in parallel and at the input signal sample rate, the output of the first sample memory being connected to the first output of the selection unit and the output of the second sample memory being connected to the second output of the selection unit.
Claim 5
Dependent Claim
84 words
Apparatus as claimed in Claim 2 or Claim 3, characterised in that the interpolator has first and second inputs connected to the first and second outputs of the selection unit respective said interpolator being provided with first means for selecting the samples applied to the first input samples required to perform the interpolation, second means for selecting from samples applied to the second input samples required for the interpolation and means for interpolating between the samples selected by the first and second selecting means.
Claim 6
Dependent Claim
39 words
Apparatus as claimed in any preceding claim, characterised in that the television picture comprises first and second interlaced fields and that a separate field store is provided for each field, each field store having said first and second parts.
Claim 7
Dependent Claim
57 words
Apparatus as claimed in any preceding claim, characterised in that said means for supplying samples to the output comprises an interleaving unit which interleaves samples read from the first and second-parts of the field store to produce successive samples at the output which samples are derived alternately from the first and second parts of the field store.
Claim 8
Dependent Claim
54 words
Apparatus as claimed in Claim 6, characterised in that the interleaving unit has a first input for receiving samples read out from the first part of the field store, a second input for receiving samples read out from the second part of the field store and an output which the interleaved samples become available.
References Cited (Backward Citations)
US4225929A
Cited
GB2073988A
Cited
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