Motion detection method, motion detection program, storage medium in which motion detection program is stored, and motion detection apparatus

A processor which executes a program to implement a method of detecting motion of a particular part from a sequence of successive input images, the program comprising the steps of:

• detecting motion vectors of a plurality of parts of the input images by tracking feature points in the successive input images;
• and
• detecting the motion of the particular part by processing the motion vectors
• the motion detection step including
• producing a histogram of the motion vectors,
• processing the histogram such that a mountain-like distribution segment each having a peak at which a frequency distribution of motion vectors has a maximum in the histogram are classified, and a mountain-like distribution segment corresponding to the particular part is detected,
• defining class information for each feature point to indicate whether each feature point belongs or does not belong to the mountain-like distribution segment detected in the histogram processing step, and
• calculating motion of the particular part by analyzing the motion vectors belonging to the mountain-like distribution segment detected in the histogram processing step, the histogram processing step including
• detecting the mountain-like distribution segment corresponding to the particular part on the basis of the class information defined for feature points.

A non-transitory computer-readable storage medium in which a program is stored, the program being executable by processing means to implement a method of detecting motion of a particular part from a sequence of successive input images, the program comprising the steps of:

• detecting motion vectors of a plurality of parts of the input images by tracking feature points in the successive input images;
• and
• detecting the motion of the particular part by processing the motion vectors, the motion detection step including
• producing a histogram of the motion vectors,
• processing the histogram such that a mountain-like distribution segment each having a peak at which a frequency distribution of motion vectors has a maximum in the histogram are classified, and a mountain-like distribution segment corresponding to the particular part is detected,
• defining class information for each feature point to indicate whether each feature point belongs or does not belong to the mountain-like distribution segment detected in the histogram processing step, and
• calculating motion of the particular part by analyzing the motion vectors belonging to the mountain-like distribution segment detected in the histogram processing step, the histogram processing step including
• detecting the mountain-like distribution segment corresponding to the particular part on the basis of the class information defined for feature points.

A motion detection apparatus configured to detect motion of a particular part from a sequence of successive input images, the apparatus comprising:

• a motion vector detection unit configured to detect motion vectors of a plurality of parts of the input images by tracking feature points in the successive input images;
• and
• a motion detection unit configured to detect the motion of the particular part by processing the motion vectors, the motion detection unit including
• a histogram producing unit configured to produce a histogram of the motion vectors,
• a histogram processing unit configured to process the histogram such that a mountain-like distribution segment each having a peak at which a frequency distribution of motion vectors has a maximum in the histogram are classified, and a mountain-like distribution segment corresponding to the particular part is detected,
• a feature point classifying unit configured to classify feature points into a class of feature points belonging to the mountain-like distribution segment detected by the histogram processing unit and a class of the other feature points, and
• a motion calculating unit configured to calculate motion of the particular part by analyzing the motion vectors belonging to the mountain-like distribution segment detected by the histogram processing unit, the histogram processing unit configured to detect the mountain-like distribution segment corresponding to the particular part on the basis of the class information defined for feature points.