Method and apparatus for processing images of facial expressions
AssigneeHitachi, Ltd.
InventorsHiroshi Sako, Anthony Smith, Mark Whitehouse
Life of this patent
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Abstract
A real time output containing data relating to states of facial parts is generated. A facial area detection unit (11) has monitoring (51-57) and determining (59-61) processing circuits operating in a pipelining manner to determine position of the facial area. The monitoring circuits (51-57) monitor pixel value frequency using 3D histogram and backprojection processing. The generating facial area signal has masks applied by a unit (12) which supplies data to mouth area and eye area detection units (14,15). Each of these operate on similar principles to the facial area detection unit (11).
Claims19
An image processing apparatus comprising:
- means for receiving a color facial image data stream in digital format;
- a plurality of image data processing circuits interconnected for real time processing the image data in a pipelining manner to provide a real time output, the circuits comprising:
- means for monitoring color values in the image data to identify image data pixels representing facial parts, and monitoring means comprising means for carrying out three-dimensional color histogram matching to monitor frequency of occurrence of pixel values in the image data and a backprojection means for comparing a generated histogram with a template histogram generated off-line, and
- means for determining states of the facial parts by monitoring positional coordinates of the identified pixels, said means for determining further comprising a counter for determining the area of the facial part or parts;
- and
- an output device outputting the determined facial part state data in real time.
A method of processing facial image data, the method comprising the steps of:
- receiving a digital color image data stream;
- monitoring color values in the image data to identify image data pixels representing facial parts, said monitoring step comprising sub-steps of carrying out three-dimensional color histogram matching in which there is backprojection with comparison of a generated three-dimensional color histogram with a template histogram generated off-line;
- determining states of the facial parts by monitoring positional coordinates of the identified pixels and using a counter to determine the area of the facial parts, said monitoring and determining steps being carried out by processing circuits interconnected for real time processing the image data in a pipelining manner;
- and
- outputting in real time a signal representing the determined facial part state data.
Dependencies are inferred from the claim text.