Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
111 words
An apparatus for identifying, in an interlaced video recording, the frames of an original cine-film sequence from which the video recording has been derived, the apparatus comprising: means for receiving a sequence of video fields comprising the video recording; means for evaluating for each successive pair of fields a function measuring correlation between adjacent odd and even picture lines taken from the first and second fields of the pair respectively; means for comparing the correlation function of each field pair with that of at least one neighboring pair in the sequence; and means for identifying pairs with greater correlation than their neighbours as being derived from the same original film frame.
Claim 2
Independent Claim
111 words
An apparatus for identifying, in an interlaced video recording, the frames of an original cine-film sequence from which the video recording has been derived, the apparatus comprising: means for receiving a sequence of video fields comprising the video recording; means for evaluating for each successive pair of fields a function measuring correlation between adjacent odd and even picture lines taken from the first and second fields of the pair respectively; means for comparing the correlation function of each field pair with that of at least one neighboring pair in the sequence; and means for identifying pairs with greater correlation than their neighbours as being derived from the same original film frame.
Claim 3
Dependent Claim
28 words
An apparatus as claimed in claim 1, wherein the correlation function is evaluated twice for each pair of fields, reversing the roles of the first and second fields.
Claim 4
Dependent Claim
81 words
An apparatus as claimed in claim 1, wherein to identify each original film frame a kernel of three successive fields is selected and the correlation function evaluated and compared for the first pair and the second pair of fields in the kernel, whereupon the pair with greater correlation is identified as a `best` candidate pair for identification as a film frame and the kernel is advanced in the received sequence of video frames for the identification of the next film frame.
Claim 5
Dependent Claim
39 words
An apparatus as claimed in claim 3, wherein the kernel is advanced in accordance with a preferred step size of at least two fields, which preferred step size is adapted to a pull-down pattern specified for the video recording.
Claim 6
Dependent Claim
45 words
An apparatus as claimed in claim 4, further comprising means for detecting disruption of the specified pull-down pattern, and for causing the kernel to be advanced in accordance with a step size different to the preferred step size until the specified pull-down pattern is restored.
Claim 7
Dependent Claim
45 words
An apparatus as claimed in claim 5, wherein the preferred step size defines also a `preferred` candidate field pair, and wherein the means for detecting disruption of the pull-down pattern operates by detecting when the `best` candidate pair is different to the `preferred` candidate pair.
Claim 8
Dependent Claim
27 words
An apparatus as claimed in claim 4, wherein the preferred step size alternates between two fields and three fields after the identification of each successive film frame.
Claim 9
Dependent Claim
42 words
An apparatus as claimed in claim 1, yet further comprising means for detecting a discrepancy between the number of received video fields and the number of identified film frames, and for correcting the discrepancy by discarding and inserting frame identifications as necessary.
Claim 10
Dependent Claim
40 words
An apparatus as claimed in claim 1, further comprising means for generating an output sequence of frames by interleaving lines from identified pairs of video fields to generate an output sequence of video frames corresponding to the identified film frames.
Claim 11
Dependent Claim
12 words
A video rate convertor including an apparatus as claimed in claim 9.
Claim 12
Dependent Claim
29 words
A motion picture encoder including an apparatus as claimed in claim 9, and further including and means for encoding the generated sequence of output frames for transmission or storage.
Claim 13
Dependent Claim
40 words
A motion picture encoder as claimed in claim 11, wherein the encoder implements inter-frame predictive coding, and wherein the apparatus yet further includes means for detecting scene cuts by detecting candidate field pairs with less correlation than their neighboring pairs.