Methods and apparatus for motion estimation using causal templates

A method of encoding a current block of a current frame of a video sequence, the method comprising the steps of:

• generating a prediction error signal corresponding to the current block by motion estimating the current block using previously reconstructed samples from the current frame associated with the current block to identify previously reconstructed best estimate samples from a reference frame whereby a motion vector representing a coordinate position difference between the respective samples in the current frame and the reference frame is calculated;
• and
• outputting the prediction error without sending the motion vector for decoding by a corresponding decoder.

Apparatus for generating a motion vector associated with a current block of a current frame of a video sequence, the apparatus comprising:

• at least one processing device operative to search at least a section of a reference frame to identify previously reconstructed samples from the reference frame that best estimate motion associated with previously reconstructed samples from the current frame associated with the current block whereby a motion vector is computed identifying the location of the previously reconstructed samples from the reference frame that best estimate the previously reconstructed samples from the current frame associated with the current block;
• and
• memory coupled to the at least one processing device operative to store previously reconstructed samples associated with the current frame and the reference frame.