Tracking apparatus for tracking target subject in input image

1. A tracking apparatus comprising:

a tracking target subject specifying unit configured to specify a tracking target subject included in input image data;

a first tracking position detection unit configured to luminance information from the image data and set, as a first candidate tracking position, the position of the tracking target subject in the image data in accordance with the luminance information;

a second tracking position detection unit configured to detect first color information from the image data and detect, as a second candidate tracking position, the position of the tracking target subject in the image data in accordance with the first color information;

a reference information acquisition unit configured to acquire second color information which is present at the first candidate tracking position; and

a control unit configured to decide a true tracking position in accordance with a determination on whether the first color information and the second color information characteristically correspond to each other and a determination on whether the distance between the first candidate tracking position and the second candidate tracking position is smaller than a predetermined distance;

wherein the control unit sets the first candidate tracking position as the true tracking position, when the distance between the first candidate tracking position and the second candidate tracking position is greater than the predetermined distance, and the control unit sets the second candidate tracking position as the true tracking position, when the distance between the first candidate tracking position and the second candidate tracking position is smaller than the predetermined distance;

the second tracking position detection unit acquires a region having the first color information in the image data, and detects the second candidate tracking position based on the acquired region; and

the control unit determines that the distance between the first candidate tracking position and the second candidate tracking position is smaller than the predetermined distance when the first candidate tracking position is included in the acquired region having the first color information, and the control unit determines that the distance between the first candidate tracking position and the second candidate tracking position is greater than the predetermined distance when the first candidate tracking position is not included in the acquired region having the first color information.

2. The tracking apparatus according to claim 1 , wherein the first tracking position detection unit and the second tracking position detection unit detect the first candidate tracking position and the second candidate tracking position in accordance with the true tracking position at the time of a next input of the image data.

3. A tracking method comprising:

causing a tracking target subject specifying unit to specify a tracking target subject included in input image data;

causing a first tracking position detection unit to detect luminance information from the image data and detect, as a first candidate tracking position, the position of the tracking target subject in the image data in accordance with the luminance information;

causing a second tracking position detection unit to detect first color information from the image data and detect, as a second candidate tracking position, the position of the tracking target subject in the image data in accordance with the first color information;

causing a reference information acquisition unit to acquire second color information which is present at the first candidate tracking position; and

causing a control unit to decide a true tracking position in accordance with a determination on whether the first color information and the second color information characteristically correspond to each other and a determination on whether the distance between the first candidate tracking position and the second candidate tracking position is smaller than a predetermined distance;

wherein the control unit sets the first candidate tracking position as the true tracking position, when the distance between the first candidate tracking position and the second candidate tracking position is greater than the predetermined distance, and the control unit sets the second candidate tracking position as the true tracking position, when the distance between the first candidate tracking position and the second candidate tracking position is smaller than the predetermined distance;

the second tracking position detection unit acquires a region having the first color information in the image data, and detects the second candidate tracking position based on the acquired region; and

the control unit determines that the distance between the first candidate tracking position and the second candidate tracking position is smaller than the predetermined distance when the first candidate tracking position is included in the acquired region having the first color information, and the control unit determines that the distance between the first candidate tracking position and the second candidate tracking position is greater than the predetermined distance when the first candidate tracking position is not included in the acquired region having the first color information.

4. A tracking apparatus according to claim 1 , further comprising a display element configured to display a tracking frame on a position determined as the true tracking position in the input image.

5. A tracking apparatus according to claim 1 , wherein the input image is obtained from an imaging element.