Face detecting method depending on image

• US 20030068083A1
• Filed: 10/01/2002
• Published: 04/10/2003
• Est. Priority Date: 10/05/2001
• Status: Abandoned Application

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Heon Jun, Lee, Jin Soo, Yu, Jae Shin
• Application Number:
  US10/263,054
• Publication Number:
  US 20030068083A1
• Time in Patent Office: Days
• US Class Current: 382/164
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G06V 40/161 Detection; Localisation; Normalisation

Abstract

The present invention is provided a face detecting method depending on image that includes a step of obtaining a color group mainly distributed in a given image; a step of designating a color group corresponding to a human color in the obtained color groups; and a step of segmenting a portion composed with pixels corresponding to color group of a human color.

Here, a step of cognizing a face may be further included.

Further, the step of obtaining mainly distributed color groups comprises a step of composing a color histogram of the image; a step of obtaining an bin (b_max) having the maximum bin value of the color histogram; a step of measuring similarity between a representative color value of the b_max and a representative color value of other respective bins; a step of designating the range of color of a main color by using bins, where measured similarity is below a critical value, and b_max; and a step of designating a representative color of the main color.

Also, a step of detecting bin corresponding to the extracted main color from the color histogram, a step of calculating the maximum bin for the rest of bins, and a step of designating a main color group in addition when the maximum bin is above a critical value are further comprised.

Claims

1. A face detecting method depending on an image, comprising:

a step of obtaining a color group mainly distributed in the image;

a step of designating a color group corresponding to a human color in the obtained color groups; and

a step of segmenting a portion composed with pixels corresponding to color group of a human color.

2. The face detecting method depending on an image according to claim 1, wherein the step of obtaining mainly distributed color group, comprising:

a step of composing a color histogram of the image;

a step of obtaining an bin (b_max) having the maximum bin value of the color histogram;

a step of measuring similarity between a representative color value of the b_max and a representative color value of other respective bins;

a step of designating the range of color of a main color by using bins, where measured similarity is below a critical value, and b_max; and

a step of designating a representative color of the main color.

3. The face detecting method depending on an image according to claim 2, wherein a step of detecting bin corresponding to the extracted main color from the color histogram, a step of calculating the maximum bin for the rest of bins, and a step of designating a main color group in addition when the maximum bin is above a critical value are further comprised.

4. The face detecting method depending on an image according to claim 1, wherein in the step of designating a color group corresponding to the portion of a human color of the obtained color groups, if the representative color of the obtained color group belongs to the predetermined range of a human color, the representative color is designated as color group of a human color portion.

5. The face detecting method depending on an image according to claim 4, wherein the predetermined range of a human color is judged as a human color when B>

G, G>

100, and B+15<

R<

B+50 where a color coordinate is RGB and ranges of each coordinates of R, G, and B belong between 0 and 255, respectively.

6. The face detecting method depending on an image according to claim 4, wherein the predetermined range of a human color is judged as a human color when G>

B, B>

100, and G+15<

R<

G+50 where a color coordinate is RGB and ranges of each coordinates of R, G, and B belong between 0 and 255, respectively.

7. The face detecting method depending on an image according to claim 4, wherein the predetermined range of a human color is judged as a human color when 134<

Cb<

155, 91<

Cr<

142, and 60<

Y<

230, where color coordinate is YCrCb and can be expressed by 24 bits.

8. A face detecting method depending on an image, comprising:

a step of obtaining a color group mainly distributed in the image;

a step of designating a color group corresponding to a human color in the obtained color groups;

a step of segmenting a portion composed with pixels corresponding to color group of a human color; and

a step of cognizing a face for judging whether the segmented portion corresponds to a face or not by comparing the segmented portion with a face template.

9. The face detecting method depending on an image according to claim 8, wherein the step of obtaining mainly distributed color group, comprising:

a step of composing a color histogram of the image;

a step of obtaining an bin (b_max) having the maximum bin value of the color histogram;

a step of measuring similarity between a representative color value of the b_max and a representative color value of other respective bins;

a step of designating the range of color of a main color by using bins, where measured similarity is below a critical value, and b_max; and

a step of designating a representative color of the main color.

10. The face detecting method depending on an image according to claim 9, wherein a step of detecting bin corresponding to the extracted main color from the color histogram, a step of calculating the maximum bin for the rest of bins, and a step of designating a main color group in addition when the maximum bin is above a critical value are further comprised.

11. The face detecting method depending on an image according to claim 8, wherein in the step of designating a color group corresponding to the portion of a human color of the obtained color groups, if the representative color of the obtained color group belongs to the predetermined range of a human color, the representative color is designated as color group of a human color portion.

12. The face detecting method depending on an image according to claim 11, wherein the predetermined range of a human color is judged as a human color when B>

G, G>

100, and B+15<

R<

B+50 where a color coordinate is RGB and ranges of each coordinates of R, G, and B belong between 0 and 255, respectively.

13. The face detecting method depending on an image according to claim 11 wherein the predetermined range of a human color is judged as a human color when G>

B, B>

100, and G+15<

R<

G+50 where a color coordinate is RGB and ranges of each coordinates of R, G, and B belong between 0 and 255, respectively.

14. The face detecting method depending on an image according to claim 11, wherein the predetermined range of a human color is judged as a human color when 134<

Cb<

155, 91<

Cr<

142, and 60<

Y<

230, where color coordinate is YCrCb and can be expressed by 24 bits.

15. The face detecting method depending on an image according to claim 8, wherein the step of cognizing a face is to judge the segmented portion as a face when the size of the segmented portion and an aspect ratio meet a condition within a desired range.

16. The face detecting method depending on an image according to claim 8, wherein the step of cognizing a face is to judge a segmented portion under a critical value as an anti-face and delete a portion under the critical value.

17. The face detecting method depending on an image according to claim 16, wherein the step of deleting a portion under a critical value is to be performed by using an opening morphology technique.