Pattern matching system and targeted object pursuit system using light quantities in designated areas of images to be compared

1. A pattern matching system that outputs a likeness value showing how much a first and a second image compare to each other, said pattern matching system comprising:

a designation block that designates as data to be compared first and second digital image data comprising all pattern area data generated from individual pattern areas in said first and second images, respectively, and said first and second digital image data not including any area data generated from pattern areas outside of said first and second images, said first and second digital image data comprising 2^x number of pattern area data wherein x is a positive integer, data levels of said pattern area data varying according to the intensity of light incident to a pattern area, said first and second images comprising 2^x number of said pattern areas;

a comparison block that compares said data levels of said pattern area data corresponding to said pattern areas at the relatively same location in said first and second images;

a calculation block that calculates said likeness value, said likeness value varying according to the number of said pattern areas where the absolute value of the difference between said compared data levels of said pattern area data of said first and second images is less than a predetermined standard value; and

an output block that outputs said likeness value,

wherein said pattern area is broadened when the intensity of light of said entire first or second image is lower than a first threshold value.

2. A pattern matching system according to claim 1 , further comprising:

a data converter that converts said data levels of said area data included in said first and second digital image data into binary values, and said comparison block comparing binary data levels of said pattern areas at the relatively same location in said first and second images.

3. A pattern matching system according to claim 1 , further comprising:

a signal receiver and a data generator, said data receiver receiving pixel signals generated by said pixels within said pattern area, signal levels of said pixel signals varying according to the light intensity incident to said pixels, said data generator generating said area data based on said pixel signals of a single pattern area; and

wherein said data generator generates large area data as said area data when the intensity of light of said entire first or second image is lower than said first threshold value, data levels of said large area data varying according to the intensity of light incident to a large pattern area, said large pattern area being said broadened pattern area,

wherein said comparison block compares data levels of said large area data corresponding to said large pattern areas at the relatively same location in said first and second images when the intensity of light of said entire first or second image is lower than said first threshold value, and

wherein said calculation block calculating said likeness value according to the number of said large pattern areas where the absolute value of the difference between said compared data levels of said large area data of said first and second images is less than said predetermined standard value.

4. A targeted object pursuit system that pursues the movement of a targeted object within a plurality of sequentially captured images, said targeted object pursuit system comprising:

a first setting block that initially designates a partial area located at a predetermined location in said captured image as a pursuit area for pursuing said targeted object;

a second setting block that designates areas displaced from said pursuit area in a first and second direction as a first and second candidate area, respectively;

a recognition block that extracts a standard image corresponding to said pursuit area from said captured image captured at a first timing, said recognition block extracting a first and second candidate image corresponding to said first and second candidate areas, respectively, from said captured image captured at a second timing which is subsequent to said first timing;

a data generator that generates pattern area data from individual pattern areas in said standard image and said first and second images, respectively, and not from pattern areas outside of said standard image and said first and second images, the data level of said pattern area data varying according to the intensity of light incident to a pattern area, said standard image and said first and second images comprising 2^x number of said pattern areas wherein x is a positive integer;

a comparison block that compares said data level of said area data corresponding to said pattern areas at the relatively same location in said standard image and one of either said first or second images;

a calculation block that calculates said likeness value, said likeness value varies according to the number of said pattern areas where the absolute value of the difference between said compared data levels of said pattern area data is less than a predetermined standard value;

a determination block that determines which direction said targeted object moves during a period between said first and second timing to be either said first or said second direction based on the difference between said likeness value of said standard image and said first candidate image and said likeness value of said standard image and said second candidate image; and

a re-designation block that re-designates a candidate area corresponding to said determined direction where said targeted object moved as said new pursuit area,

wherein said pattern area is broadened when the intensity of light of said entire first or second image is lower than a first threshold value.

5. A targeted object pursuit system according to claim 4 ,

wherein said second setting block designates said first and second candidate areas so that the distance between said pursuit area and a first and second areas increases according to a focal length of a photographic optical system, an optical image of said targeted object passing through said photographic optical system.

6. A targeted object pursuit system according to claim 4 , further comprising:

an exposure adjustment system that can carry out the exposure adjustment for an optical image of said targeted object received by an imaging device according to the intensity of light of a part of said optical image, and said intensity of light incident to said pattern area being used for said intensity of light of a part of said optical image for said exposure adjustment.