Patent ID: 6898244

Claim:
A movement vector generating apparatus for generating a movement vector for a movement compensation by means of an inter-frame prediction, when encoding image information including an image of a plurality of frames by using the movement compensation, said apparatus comprising: a plurality of generating devices each for generating a we movement vector corresponding to a search range and a search accuracy between one frame and another frame, for each pixel block which is located within said one frame respectively in the image information and includes a plurality of pixels, said generating devices respectively using search ranges different from each other and search accuracies different from each other; and a selecting device for selecting one of the movement vectors generated by said generating devices, in accordance with characteristics of the image in said each pixel block, and then outputting the selected movement vector corresponding to said each pixel block, wherein said generating devices comprise: a first generator for generating a first movement vector, with a preset first range as the search range; and a second generator for generating a second movement vector at a search accuracy lower than that of the first movement vector, with a preset second range wider than the first range as the search range, and wherein said selecting device comprises: a first adding device for adding together absolute values of differences between a respective one of the pixels in the pixel block and its corresponding pixel in the frame targeted by the movement compensation, for all of the pixels in the pixel block, in said first generator to generate a first absolute value sum; a second adding device for adding together absolute values of differences between a respective one of the pixels in the pixel block and its corresponding pixel in the frame targeted by the movement compensation, as for all of the pixels in the pixel block, in said second generator, to generate a second absolute value sum; and a standardizing device for standardizing the generated first and second absolute value sums, respectively, said selecting device comparing the standardized first absolute value sum with the standardized second absolute value sum, outputting the first movement vector as the selected movement vector if a difference between the standardized first absolute value sum and the standardized second absolute value sum is not greater than a predetermined threshold which is set in advance to detect a difference between the first movement vector and the second movement vector at a high accuracy, and outputting the second movement vector as the selected movement vector if the difference between the standardized first absolute value sum and the standardized second absolute value sum is greater than the predetermined threshold.