Real-time face tracking in a digital image acquisition device

An image processing apparatus including one or more processors and one or more digital storage media having digitally-encoded instructions embedded therein for programming the one or more processors to perform an iterative method of recognizing faces in an image stream, the method comprising:

• a. providing a database comprising an identifier and associated parameters for each of a number of one or more faces to be recognized;
• b. receiving a new acquired image from an image stream;
• c. applying face detection to at least a portion of said acquired image to provide a set of one or more candidate face regions, each candidate face region having a given size and a respective location;
• d. selectively applying face recognition using said database to at least one of said candidate face regions to provide an identifier for a face recognized in a candidate face region;
• and
• e. storing a portion of said image including the recognized face in association with at least one image of said image stream.

A method of tracking faces in an image stream with a digital image acquisition device, comprising:

• a. receiving an acquired image from an image stream including one or more face regions;
• b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image;
• c. calculating a corresponding integral image for a least a portion of said sub-sampled image;
• d. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions each having a given size and a respective location;
• e. merging said set of candidate face regions with one or more previously detected face regions to provide a set of candidate face regions of different sizes or locations or both.

A method of detecting faces in an image stream using a digital image acquisition device, comprising:

• a. receiving an acquired image from said image stream including one or more face regions;
• b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image;
• c. identifying one or more regions of said acquired image as candidate face regions;
• d. calculating a corresponding integral image for a least one of said candidate face regions of said sub-sampled acquired image;
• e. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions each having a given size and a respective location;
• and
• f. for at least one candidate face region associated with a previous image, enhancing the contrast of the luminance characteristics of the corresponding region of said acquired image.

An image processing apparatus including one or more processors and one or more digital storage media having digitally-encoded instructions embedded therein for programming the one or more processors to perform an iterative method of tracking faces in an image stream with a digital image acquisition device, wherein the method comprises:

• a. receiving an acquired image from an image stream including one or more face regions;
• b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image;
• c. calculating a corresponding integral image for a least a portion of said sub-sampled image;
• d. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions each having a given size and a respective location;
• e. merging said set of candidate face regions with one or more previously detected face regions to provide a set of candidate face regions of different sizes or locations or both.

An image processing apparatus including one or more processors and one or more digital storage media having digitally-encoded instructions embedded therein for programming the one or more processors to perform an iterative method of detecting faces in an image stream using a digital image acquisition device, wherein the method comprises:

• a. receiving an acquired image from said image stream including one or more face regions;
• b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image;
• c. identifying one or more regions of said acquired image as candidate face regions;
• d. calculating a corresponding integral image for a least one of said candidate face regions of said sub-sampled acquired image;
• e. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions each having a given size and a respective location;
• and
• f. for at least one candidate face region associated with a previous image, enhancing the contrast of the luminance characteristics of the corresponding region of said acquired image.