Motion estimation method and apparatus for interrupting computation which is determined not to provide solution

A motion estimation apparatus, comprising:

• means for selecting one of blocks to be searched for sequentially selecting one of blocks to be searched in a search range;
• absolute difference accumulating means for sequentially calculating differences between corresponding sample values of a first reference block and said one of blocks to be searched and accumulating absolute values of differences;
• accumulation operation interrupting means connected to an output of said absolute difference accumulating means for comparing an intermediate result of the accumulated value and a prescribed threshold value every time when differences between corresponding sample values of said first reference block and said one of blocks to be searched are calculated prescribed times and for interrupting the operation of said absolute difference accumulating means when said intermediate result exceeds said prescribed threshold value;
• and
• correspondence means for making said one of blocks to be searched having a minimum final result of said accumulated value correspond to said reference block,
• wherein the prescribed threshold value is dependent on one of the following values,
• 1) an intra evaluation value of said first reference block, which is a sum obtained by accumulating absolute values of sample data in said first reference block,
• 2) an absolute difference sum calculated for a second reference block in a preceding frame at the same position as the first reference block in a current frame, and
• 3) an absolute difference sum calculated for a second reference block different from said first reference block in a same frame.

A motion estimation apparatus, comprising:

• means for selecting one of blocks to be searched for sequentially selecting one of blocks to be searched in a search range;
• a plurality of registers each holding a sample value of said one of blocks to be searched and receiving a value of an adjacent register;
• a plurality of processing means connected to each of said plurality of registers for sequentially calculating differences between corresponding sample values of a reference block and said one of blocks to be searched, accumulating absolute values of differences, comparing an accumulated value and a prescribed threshold value dependent on said reference block and interrupting an operation when said accumulated value exceeds said prescribed threshold value;
• means connected to said plurality of processing means for storing a calculation result of said processing means when said calculation result of said processing means is smaller than said prescribed threshold value;
• and
• threshold value managing means for applying said prescribed threshold value to each of said plurality of processing means, increasing said prescribed threshold value by a given amount and again applying said prescribed threshold value to said plurality of processing means when all of said plurality of processing means are interrupted as all accumulated values exceed said prescribed threshold value.