Detection of a 3:2 pulldown in a motion estimation phase and optimized video compression encoder
AssigneeSTMicroelectronics S.r.l.
InventorsLuca Pezzoni, Emiliano Piccinelli, Danilo Pau
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Abstract
A method for compressing encoding data of a sequence of pictures is based on a motion estimation among the successive images to remove the temporal redundancy from the data. The method recognizes a 3:2 pulldown conversion of a series of photograms of a filmed sequence in a sequence of TV frames. The TV frames have a number greater than the number of the photograms by duplicating certain pictures in a certain order. The redundancy due to such picture duplications is eliminated.
Claims11
A method for compressing encoding data of a sequence of pictures based on a motion estimation among successive images to remove temporal redundancy from the data being encoded, the method comprising:
- detecting a 3:2 pulldown conversion of a series of photograms of a filmed sequence in a sequence of TV frames having a number greater than a number of the photograms by duplication of certain pictures in a certain order, a full field of each frame being divided into a plurality of macroblocks;
- detecting a field duplication by counting the number of macroblocks remaining fixed or undergoing a negligible shift between two consecutive fields, and comparing the count with a threshold for determining if the field is being duplicated;
- and
- eliminating the temporal redundancy due to the detected field duplications.
An MPEG2 encoder comprising:
- a motion estimator among successive frames to remove temporal redundancy from data to be compressed;
- detection means for recognizing a 3:2 pulldown of conversion of a series of a certain number of photograms of a filmed sequence in a sequence of TV frames having a number greater than a number of the photograms by duplication of certain pictures in a certain order, a full field of each frame being divided into a plurality of macroblocks;
- counter means for detecting a field duplication by counting the number of macroblocks remaining fixed or undergoing a negligible shift between two consecutive fields;
- comparing means for comparing the count with a threshold for determining if the field is being duplicated;
- and
- elimination means for eliminating the redundancy due to the detected field duplications.
Dependencies are inferred from the claim text.