Apparatus and method for performing mixed motion estimation based on hierarchical search

An apparatus for performing motion estimation, the apparatus comprising:

• a first memory for storing current image data as a reference block having a predetermined size;
• a second memory for storing previous image data as a search region for searching-motion vectors;
• a motion estimation skip unit for receiving motion vectors and SAD values of the previous image data, compensating for the motion of the current image data, and determining whether or not motion estimation for the current image data is skipped based on the compensation result of the current image data;
• a motion estimation unit for receiving the current image data and the previous image data from the first and second memories to perform motion estimation for the current image data;
• a comparator for outputting the minimum value of estimation results output from the motion estimation unit as a final motion estimation result;
• a multiplexer for selecting and outputting any one of the compensation result generated from the motion estimation skip unit and the final estimation result generated from the comparator based on the determination result of the motion estimation skip unit;
• an address generator for outputting addresses related to the motion estimation and the motion compensation to the first and second memories;
• and
• a controller for controlling the operation of the motion estimation skip unit and the operation of generating the addresses in the address generator based on the determination of the motion estimation skip unit.