1. A motion detection apparatus for detecting a motion of an object, comprising: an image pickup section picking up a motion image and successively clipping a time series of frame images; a feature extracting section extracting a first feature area, representing a feature of the object, from a first frame image among the time series of frame images; a feature area standardizing section standardizing a size of the first feature area to be set as a first standardized feature area; a mask generating section setting an area on the first frame image, which is a complement of the first standardized feature area in the first frame image, as a first masked area; a balloting section resetting a count value associated with each pixel when the relevant pixel is located on the first masked area, and incrementing the count value when the relevant pixel is located on a first on-masked area that is the first standardized feature area; and shift speed calculating section calculating a shift direction and shift speed of the first feature area based on a spatial gradient of the count values, accumulated for the time series of frame images, associated with the pixels located on the first standardized feature area, wherein the feature extracting section detects a corner edge component of the object as the first feature area.