VIDEO ENCODING DEVICE

摘要

An image encoding device that appropriately estimates a prediction vector by avoiding an uncoded macro block (MB) is disclosed. The device determines a start point of searching a motion vector for an encoding target region, from the prediction vector for the target region which is determined with motion vectors for surrounding blocks around the target region and in accordance with a predetermined rule, and starts searching for the motion vector from the search start point. If the size of the encoding target region cannot be acquired during calculation of the prediction vector, the device determines the size of the encoding target region, from the size of an encoded region other than the target region. If at least one of the motion vectors for the surrounding blocks cannot be acquired, the device calculates the prediction vector using alternatively a motion vector of an encoded block outside of the target region.

主权项

1. An image encoding device which encodes an image by searching for a motion vector for an encoding target region that is a region in a target image to be encoded, and by subjecting the target image to an inter prediction, on the basis of the motion vector for the encoding target region, the image encoding device comprising:
a motion search section determining a search start point of the motion vector for the encoding target region, from a prediction vector that is a motion vector determined in accordance with a preset rule, the prediction vector being a motion vector for the encoding target region to be predicted, the preset rule being defined in advance with motion vectors for surrounding blocks positioned around the encoding target region, the motion search section starting searching for the motion vector for the encoding target region from the search start point; a prediction vector estimating section, when a size of the encoding target region cannot be acquired in calculating the prediction vector in accordance with the preset rule, determining the size of the encoding target region, from a size of an encoded region in the target image other than the encoding target region, thereby calculating the prediction vector, and when at least one of the motion vectors for the surrounding blocks cannot be acquired, calculating the prediction vector, from a motion vector for an encoded region in the target image other than the encoding target region; and a variable-length encoding section encoding a difference between the prediction vector and the motion vector for the encoding target region which the motion search section has searched for.