Image collation method and apparatus and recording medium storing image collation program

An image collation apparatus comprising:

• first collation means (20, 22) for obtaining a relationship between first and second images for each collation unit by collating the first and second images with each other;
• minimum coincidence ratio extraction means (31) for obtaining a minimum coincidence ratio from coincidence ratios in the relationship obtained from said first collation means;
• region designation means (65) for sequentially designating a plurality of collation regions predetermined as regions in which the first and second images are collated with each other,
• maximum coincidence ratio extraction means (30) for obtaining a maximum coincidence ratio from coincidence ratios output from said first collation means (20, 22),
• computation means (40) for obtaining a difference between the maximum coincidence ratio output from said maximum coincidence ratio extraction means (30) and the minimum coincidence ratio output from said minimum coincidence ratio extraction means (31), and
• determination means (50) for determining that the first and second images are identical, if the difference output from said computation means (40) is not less than a predetermined threshold, and said first collation means obtains coincidence ratios by sequentially collating the first and second images within the collation regions designated by said region designation means (65).

An image collation method comprising:

• recording a second image as a registered image;
• collating a first image with the registered image to obtain a plurality of coincidence ratios;
• extracting a minimum coincidence ratio from the plurality of coincidence ratios obtained from collating;
• determining that the first image and a registered image are identical if the extracted minimum coincidence ratio is smaller than a predetermined threshold value,
• extracting a maximum coincidence ratio from coincidence ratios output in the collating,
• determining a difference between the maximum coincidence ratio and the minimum coincidence ratio, and
• determining that the first and second images are identical if the difference between the maximum coincidence ratio and the minimum coincidence ratio is not less than the predetermined threshold.

An image collation method comprising:

• a first collating to obtain a relationship between a first image and a second image by collating the first image and the second image with each other;
• extracting a minimum coincidence ratio by obtaining the minimum coincidence ratio from coincidence ratios in the relationship obtained in the first collating;
• determining that the first and second images are identical if the extracted coincidence ratio is smaller than a predetermined threshold;
• and
• sequentially designating a plurality of collation regions predetermined as regions in which the first and second images are collated with each other,
• obtaining a maximum coincidence ratio from coincidence ratios output in the first collating, and
• obtaining a difference between the maximum coincidence ratio and the minimum coincidence ratio,
• wherein coincidence ratios are obtained by sequentially collating the first and second images within the collation regions.

A recording medium storing image collation program instructions for causing a computer to execute:

• recording a second image as a registered image;
• collating a first image with the registered image to obtain a plurality of coincidence ratios;
• extracting a minimum coincidence ratio from the plurality of coincidence ratios obtained from collating;
• and
• determining that the first image and a registered image are identical if the extracted minimum coincidence ratio is smaller than a predetermined threshold value
• extraction a maximum coincidence ratio from coincidence ratios from the plurality of coincidence ratios,
• determining a difference between the maximum coincidence ratio and the minimum coincidence ratio, wherein the first and second images are identical if the difference between the maximum coincidence ratio and the minimum coincidence ratio is not less than the predetermined threshold.