Apparatus and method for performing scalable hierarchical motion estimation

A method for performing motion estimation for a sequence of images, where each of said image is divided into at least one block, said method comprising the steps of:

• (a) generating a plurality of M-ary pyramids having different pyramid architectures, where each of said M-ary pyramid architectures comprises a plurality of P-bit levels, where P for at least two of said P-bit levels of at least one of said M-ary pyramid architecture is different;
• (b) selecting one of said M-ary pyramid architectures for performing hierarchical motion estimation;
• and
• (c) generating a plurality of motion vectors starting from a highest level of said selected M-ary pyramid, where said plurality of motion vectors are passed hierarchically to a lower level of said selected M-ary pyramid.

Apparatus for encoding an image sequence having at least one input frame, said apparatus comprising:

• a motion compensator for generating a predicted image of a current input frame, said motion compensator comprises an M-ary pyramid generator for generating an M-ary pyramid having a plurality of P-bit levels, where P for at least two of said P-bit levels of said M-ary pyramid is different and a motion estimation module for performing hierarchical motion estimation on said M-ary pyramid;
• a transform module for applying a transformation to a difference signal between the input frame and said predicted image, where said transformation produces a plurality of coefficients;
• a quantizer for quantizing said plurality of coefficients with at least one quantizer scale to produce a plurality of quantized coefficients;
• and
• a coder for coding said quantized coefficients into a bitstream.