Movement detection circuit, motion estimation circuit, and associated movement detection method

A motion estimation circuit, comprising:

• a background motion vector generator, for generating a plurality of temporal motion vectors related to a plurality of first-frame blocks and a plurality of second-frame blocks, and a plurality of spatial motion vectors related to the plurality of second-frame blocks;
• a motion vector selection circuit, electrically connected to the background motion vector generator;
• a movement detection circuit, for detecting movement of an object in continual frames, comprising:
• a candidate searching module, comprising:
• a first-frame candidate circuit, for locating a first first-frame candidate position and a second first-frame candidate position in a first frame based on a first-frame similarity measure distribution at a current time;
• and
• a second-frame candidate circuit, for locating a first second-frame candidate position and a second second-frame candidate position in a second frame based on a second-frame movement characteristic at the current time;
• an object selection module, electrically connected to the candidate searching module, comprising:
• a first-frame object selection circuit, electrically connected to the first-frame candidate circuit, for identifying which of the first and the second first-frame candidate positions is a first-frame object position representing a position of the object in the first frame according to the first-frame similarity measure distribution at the current time and another second-frame movement characteristic;
• and
• a second-frame object selection circuit, electrically connected to the second-frame candidate circuit and the first-frame object selection circuit, for identifying which of the first and the second second-frame candidate positions is a second-frame object position representing a position of the object in the second frame according to the first-frame similarity measure distribution and the second-frame movement characteristic;
• and
• a motion vector calculation circuit, electrically connected to the object selection module, for calculating an object motion vector representing the movement of the object between the first frame and the second frame based on the first-frame and the second-frame object positions,
• wherein the object motion vector is transmitted to the motion vector selection circuit and the motion vector selection circuit generates a plurality of selected motion vectors based on the plurality of spatial motion vectors, the plurality of temporal motion vectors, and the object motion vector.

A movement detection method for detecting movement of an object in continual frames, comprising steps of:

• locating a first first-frame candidate position and a second first-frame candidate position in a first frame based on a first-frame similarity measure distribution at a current time;
• locating a first second-frame candidate position and a second second-frame candidate position in a second frame based on a second-frame movement characteristic at the current time;
• identifying which of the first and the second first-frame candidate positions is a first-frame object position representing a position of the object in the first frame according to the first-frame similarity measure distribution and another second-frame movement characteristic at a previous time;
• identifying which of the first and the second second-frame candidate positions is a second-frame object position representing a position of the object in the second frame according to the first-frame similarity measure distribution and the second-frame movement characteristic;
• and
• calculating an object motion vector representing movement of the object between the first frame and the second frame based on the first-frame and the second-frame object positions.