Method and apparatus of recognizing face using 2nd-order independent component analysis (ICA)/principal component analysis (PCA)

A method of recognizing a face using 2nd-order independent component analysis (ICA), the method comprising;

• (a) receiving a first facial image to be recognized and a second facial image as a basis for comparison;
• (b) performing 2nd-order ICA on the first and second facial images, respectively, and extracting ICA coefficient vectors;
• and
• (c) determining whether there is a similarity between the ICA coefficient vectors corresponding to the first and second facial images, and outputting the determination result.

A method of searching for a face using 2nd-order ICA, the method comprising:

• (a) constructing a database (DB) in which facial images of one or more persons and identification information of the persons are stored;
• (b) receiving an arbitrary facial image to be searched for from the DB;
• (c) performing the 2nd-order ICA on the facial image to be searched for and generating ICA coefficient vectors;
• (d) sequentially reading facial images stored in the DB, and performing the 2nd-order ICA on the facial images and generating ICA coefficient vectors;
• (e) comparing the ICA coefficient vectors corresponding to the facial image received from the DB with the ICA coefficient vectors corresponding to the facial image to be searched for, and determining whether the two facial images are from the same person;
• (f) if it is determined that the two facial images are from the same person, reading identification information corresponding to the facial image from the DB and outputting the same.

A method of searching for a face using 2nd-order ICA, the method comprising:

• (a) constructing a database (DB) in which ICA coefficient vectors corresponding to facial images of one or more persons and identification information of the persons are stored;
• (b) receiving an arbitrary facial image to be searched for from the DB;
• (c) performing the 2nd-order ICA on the facial image to be searched for and generating ICA coefficient vectors;
• and
• (d) searching for ICA coefficient vectors corresponding to the facial image belonging to the same person as identified by the facial image to be searched for, according to a similarity between the ICA coefficient vectors stored in the DB and those corresponding to the facial image to be searched for, and outputting the same.

An apparatus of generating feature information comprising:

• a low-pass filtering portion which performs PCA on input original image and generates low-pass filtered image by removing high-frequency components from the original image;
• a residual image generator which subtracts the low-pass filtered image from the input original image and generates remaining image having only the high-frequency components;
• and
• an ICA coefficient matrix calculator which performs ICA on the remaining image and generates feature information corresponding to the original image.

An apparatus of recognizing a face using 2nd-order ICA, the apparatus comprising:

• an input portion which receives a first facial image to be recognized and a second facial image as a basis for comparison with the first facial image;
• a feature information generator which performs 2nd-order ICA on the first and second facial images and generates ICA coefficient matrices;
• and
• a comparator which compares an ICA coefficient vector corresponding to the first facial image with that of the second facial image to determine whether there is a similarity therebetween, and outputs the determination result.

An apparatus of searching for a face using 2nd-order ICA, the apparatus comprising:

• an input portion which receives facial images used in constructing a facial image information database (DB) for searching for a face or a facial image to be searched for among the facial images used in constructing the DB;
• a feature information generator which performs 2nd-order ICA on the facial images supplied from the input portion and generating feature information corresponding to the facial images;
• a DB managing portion which stores the feature information corresponding to the facial images used in constructing the DB, supplied from the feature information generator, and manages the information to be stored in the DB;
• and
• a comparator which receives the feature information corresponding to the facial image to be searched for, from the feature information generator, searches for feature information whose similarity with the received feature information to be searched for is greater than a predetermined reference value, and determines that the two facial images are from the same person.