Face image detecting apparatus and method of controlling same

A face image detecting apparatus for detecting a face-image portion contained in each image of a plurality of frames of images represented by continuously applied image data, comprising:

• a detecting device for detecting a value of face likeliness and position of a face-image portion contained in an image represented by applied image data;
• a displacement-amount measuring device for measuring amount of displacement between the position of the face-image portion detected by said detecting device and position of a face-image portion detected by the detecting device in a preceding frame of an image;
• a displacement-amount determination device for determining whether the amount of displacement measured by said displacement-amount measuring device is less than a threshold value;
• a face-likeliness determination device for determining whether the value of face likeliness detected by said detecting device is equal to or greater than a prescribed threshold value;
• and
• a deciding device for deciding that a person having a face-image portion at the position detected by said detecting device and a person having a face-image portion at the position detected in the preceding frame of the image are the same in response to a determination by said displacement-amount determination device that the amount of displacement is less than the threshold value and, moreover, a determination by said face-likeliness determination device that the value of face likeliness is equal to or greater than the threshold value.

A method of controlling a face image detecting apparatus, comprising the steps of:

• determining whether a value of face likeliness of a detected image portion is equal to or greater than a prescribed threshold value, the detected image portion being within an image represented by applied image data;
• storing in memory a position regarded as a face-image portion in the image;
• updating a position, which has been stored in the memory, to the position of the detected image portion upon deciding that the detected image portion is a face-image portion in response to a determination that the value of face likeliness of the face-image portion is equal to or greater than the threshold value;
• repeating the face-likeliness determination processing and the update processing with regard to a continuously applied image;
• starting timekeeping by a timer for every incidence of update processing, and deciding that while the timekeeping is in progress, a face-image portion is present at the position that has been stored in the memory;
• and
• resetting the position that has been stored in the memory, in response to a determination that the value of face likeliness of the detected image portion is less than the threshold value and, moreover, end of timekeeping by the timer.

A method of controlling a face image detecting apparatus for detecting a face-image portion contained in each image of a plurality of frames of images represented by continuously applied image data, comprising the steps of:

• detecting a value of face likeliness and position of a face-image portion contained in an image represented by applied image data;
• measuring amount of displacement between the detected position of the face-image portion and position of a face-image portion detected in a preceding frame of an image;
• determining whether the measured amount of displacement is less than a threshold value;
• determining whether the detected value of face likeliness is equal to or greater than a prescribed threshold value;
• and
• deciding that a person having a face-image portion at the detected position and a person having a face-image portion at the position detected in the preceding frame of the image are the same in response to a determination that the amount of displacement is less than the threshold value and, moreover, a determination that the value of face likeliness is equal to or greater than the threshold value.