Patent ID: 7180570

Claim:
A method for 3:2 pull-down film mode detection of a stream of NTSC video fields {F[j]}={ . . . F[n−2], F[n−1], F[n], . . . }, said method comprising the steps of: a) generating from said {F[j]} a sequence {S[j]}, wherein a S[n] in said sequence denotes an accumulated sum of absolute value of luma difference between two fields F[n] and F[n−2] over a common set of pixel positions; b) generating from said {S[j]} a sequence {P[j]} whose elements are in one-to-one correspondence with the elements of said sequence {S[j]}, wherein a P[n] is assigned a symbol from a two-symbol set by applying a set of fuzzy inference rules; and c) in response to said {P[j]} having a pattern that characterized a stream of 3:2 pull-downed fields, designating said {F[j]} as 3:2 pull-downed fields from film source.