Patent ID: 7133064

Claim:
A method for 3:2 pull-down film source detection, comprising the steps of: receiving a source; initializing coefficients to zero, the coefficients including a field index as n, a MatchCounter, a ModeCounter, an accumulated field difference accDiff, and an average field difference aveDiff; calculating a field difference FieldDiff of two fields F(n) and F(n+2) of the same type in the source; comparing the FieldDiff to a first threshold Fi_th and an adaptive threshold Adap_th; increasing the MatchCounter by 1 and setting the ModeCounter, accDiff, and aveDiff to 0 if the FieldDiff is smaller than the Fi_th and Adap_th; increasing the ModeCounter by 1, adding the FieldDiff to the accDiff, obtaining the aveDiff by dividing the accDiff with the ModeCounter, and obtaining the Adap_th from multiplying the aveDiff and a coefficient K if the FieldDiff is not smaller than the Fi_th or Adap_th; and detecting the source as a 3:2 pull-down film source if the MatchCounter is larger than 1 and the ModeCounter is equal to 0.