Patent ID: 7796189
Filing Date: 2010-09-14
Classification: H04N

Abstract:
1. A 2-2 pulldown signal detection device comprising: an inter-field correlation detection part, configured so as to detect a prescribed field signal of an input image signal and its correlation with a one field delay signal, and to output the results of detecting whether the correlation is “strong” or “weak”; an inter-frame correlation detection part, configured so as to detect said prescribed field signal of an input image signal and its correlation with a two field delay signal, and to output the results of detecting whether the correlation is “strong” or “weak”; a first decision part, configured so as to decide, when the inter-field correlation detected by said inter-field correlation detection part matches the 2-2 pulldown pattern across a prescribed number of fields, that said input image signal is a 2-2 pulldown signal; the second decision part, configured so as to decide, when an input image signal has been decided by said first decision part to be a 2-2 pulldown signal, and said inter-field correlation no longer matches the 2-2 pulldown pattern, whether, on the 2-2 pulldown pattern of said inter-field correlation, the portions that should be “strong” are “weak”; and a third decision part, configured so as to continue the decision on the 2-2 pulldown signal with respect to said input image signal, when the conditions have not been established in which the correlation between the current field and the field before its one field is “strong”, the correlation between the field before the one field of the current field and the field before the two field is “strong”, and the correlation between the current field and the field before its two field is “weak”, and when it is decided by said second decision part that on the 2-2 pulldown pattern of said inter-field correlation, the portions that should be “strong” are not “weak”.