Method and apparatus for extracting facial features from image containing face

• US 20080199055A1
• Filed: 08/30/2007
• Published: 08/21/2008
• Est. Priority Date: 02/15/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jong-ha, Kim, Jung-bae, Moon, Young-su, Park, Gyu-tae, Hwang, Won-jun
• Granted Patent: US 8,111,880 B2
• Time in Patent Office: Days
• US Class Current: 382/118
• CPC Class Codes: G06V 10/449 Biologically inspired filters, e.g. difference of Gaussians [DoG] or Gabor filters
• CPC Class Codes: G06V 40/171 Local features and components; Facial parts eye characteristics G06V40/18; Occluding parts, e.g. glasses; Geometrical relationships

Abstract

Provided are a method and apparatus for extracting facial features from an image containing a face. The method and apparatus filter an input image using a filter set for face recognition at each of predetermined locations in the input image, merge values obtained by filtering the input image at locations, which are horizontally symmetrical to each other with respect to the center of the face, and synthesize values obtained by filtering the input image at locations which are not symmetrical to each other with respect to the center of the face with the merged values. Therefore, the time, feature values, and storage space required to extract or compare facial features can be significantly reduced. In addition, a face recognition system that runs well on low specification hardware can be implemented.

Claims

1. A method of extracting facial features from an image containing a face, the method comprising:

(a) filtering the image using a filter set for face recognition at each of predetermined locations in the image;

(b) merging values obtained after the image is filtered at locations which are horizontally symmetrical to each other with respect to the center of the face; and

(c) synthesizing the values obtained by filtering the image with values obtained by merging the values.

2. The method of claim 1, wherein operation (a) comprises:

(a1) filtering the image using the filter set at the locations which are horizontally symmetrical to each other with respect to the center of the face; and

(a2) filtering the image using the filter set at locations excluding the locations, which are horizontally symmetrical to each other with respect to the center of the face, from among the predetermined locations.

3. The method of claim 2, wherein values obtained by filtering the image in operation (a1) are merged in operation (b), and values obtained by filtering the image in operation (a2) are synthesized with the values merged in operation (b) in operation (c).

4. The method of claim 1, wherein the filter set for face recognition comprises a predetermined number of filters which are classified according to scale, direction, and real number and imaginary number.

5. The method of claim 4, wherein operation (b) comprises merging two values obtained by filtering the image using symmetric filters at two locations which are horizontally symmetrical to each other with respect to the center of the face.

6. The method of claim 5, wherein operation (b) comprises averaging the two values.

7. The method of claim 5, wherein operation (b) comprises assigning a weight to a value, which is obtained by filtering the image at a reliable location, among the two values and merging the weighted value and the other value.

8. A computer-readable recording medium on which a program for executing the method of claim 1 in a computer is recorded.

9. An apparatus for extracting facial features from an image containing a face, the apparatus comprising:

a filtering unit filtering the image using a filter set for face recognition at each of predetermined locations in the image;

a merging unit merging values obtained after the image is filtered at locations which are horizontally symmetrical to each other with respect to the center of the face; and

a synthesis unit synthesizing the values obtained by the filtering unit with values obtained by the merging unit.

10. The apparatus of claim 9, wherein the filtering unit comprises:

a first filtering unit filtering the image using the filter set at the locations which are horizontally symmetrical to each other with respect to the center of the face; and

a second filtering unit filtering the image using the filter set at locations excluding the locations, which are horizontally symmetrical to each other with respect to the center of the face, from among the predetermined locations.

11. The apparatus of claim 10, wherein the merging unit merges values obtained by the first filtering unit, and the synthesis unit synthesizes values obtained by the second filtering unit with the values merged by the merging unit.

12. The apparatus of claim 9, wherein the filter set for face recognition comprises a predetermined number of filters which are classified according to scale, direction, and real number and imaginary number.

13. The apparatus of claim 12, wherein the merging unit merges two values obtained by filtering the image using symmetric filters at two locations which are horizontally symmetrical to each other with respect to the center of the face.

14. The apparatus of claim 13, wherein the merging unit averages the two values.

15. The apparatus of claim 13, wherein the merging unit assigns a weight to a value, which is obtained by filtering the image at a reliable location, from among the two values and merges the weighted value and the other value.