Method for controlling tracking using a color model, corresponding apparatus and non-transitory program storage device

A video tracker device comprising:

• a memory for storing a video image comprising at least first and second frames, each pixel in the video image having at least one color component;
• and
• a processor configured to:
• obtain a window in a second frame of a video image corresponding to a window in a first frame of the video image using a tracking algorithm in a tracking mode, wherein each pixel in the video image has at least one color component;
• compute a foreground color model for each one of at least two groups of pixels in the window in the first frame, each foreground color model comprising at least one color component computed from values of the color components of pixels in the corresponding group;
• compute a background color model for each one of at least two groups of pixels in a background area around the window in the first frame, each background color model comprising at least one color component computed from values of the color components of pixels in the corresponding group;
• determine a foreground color distance between a plurality of pixels in the window in the second frame and each of the foreground color models according to color component values and determining a foreground minimum color distance for each pixel of said plurality of pixels as a minimum of the determined foreground color distances;
• determine a background color distance between a plurality of pixels in the window in the second frame and each of the background color models according to color component values and determining a background minimum color distance for each pixel of said plurality of pixels as a minimum of the determined background color distances;
• assign a pixel confidence value for each pixel of said plurality of pixels in the second frame according to the corresponding foreground and background minimum color distances for the each pixel of said plurality of pixels in the window in the second frame;
• select among the tracking mode or a mode different from the tracking mode, based on a window confidence value for the window in the second frame, wherein the window confidence value is obtained according to the pixel confidence values of said plurality of pixels in the window in the second frame.