System and method for facial recognition using images captured from a target illuminated with infrared light
Various implementations of the invention perform facial recognition on a target image compared against a color image from an image gallery, where the target image was acquired by an infrared-sensitive camera of a target that was illuminated with infrared light. According to various implementations of the invention, a blue component and a green component of the pixels in the color image are suppressed or eliminated, and facial recognition is performed between the target image and the color-suppressed image.
1. A method for comparing images, the method comprising:
receiving a target image, wherein the target image corresponds to a target illuminated by an infrared light source during capture of the target by a camera sensitive to infrared light;
receiving a color image, the color image comprising a color image of a subject;
suppressing a blue component or a green component of a plurality of pixels in the color image to produce a color-suppressed image; and
determining whether the target matches the subject by comparing the target image with the color-suppressed image.
2. The method of claim 1 , wherein suppressing a blue component or a green component of a plurality of pixels in the color image comprises suppressing the blue component or the green component of the plurality of pixels in the color image to zero to produce the color-suppressed image.
3. The method of claim 2 , wherein suppressing the blue component or the green component of the plurality of pixels in the color image to zero to produce the color-suppressed image comprises suppressing the blue component and the green component of the plurality of pixels in the color image to zero to produce the color-suppressed image.
4. The method of claim 1 , wherein suppressing a blue component or a green component of a plurality of pixels in the color image comprises suppressing the blue component or the green component of the plurality of pixels in the color image to less than ten percent of their original value to produce the color-suppressed image.
5. The method of claim 4 , wherein suppressing the blue component or the green component of the plurality of pixels in the color image to less than ten percent of their original value to produce the color-suppressed image comprises suppressing the blue component and the green component of the plurality of pixels in the color image to less than ten percent of their original value to produce the color-suppressed image.
6. The method of claim 1 , wherein suppressing a blue component or a green component of a plurality of pixels in the color image comprises ignoring the blue component or the green component of the plurality of pixels in the color image to produce the color-suppressed image.
7. The method of claim 6 , wherein ignoring the blue component or the green component of the plurality of pixels in the color image to produce the color-suppressed image comprises ignoring the blue component and the green component of the plurality of pixels in the color image to produce the color-suppressed image.
8. The method of claim 1 , wherein receiving a target image from a camera sensitive to infrared light comprises receiving the target image from an infrared camera.
9. The method of claim 1 , wherein the infrared light source was an artificial infrared light source.
10. The method of claim 1 , wherein the infrared light source was the sun.
11. The method of claim 1 , wherein receiving a color image comprises receiving of a color image of a known subject.
12. A method for comparing images, the method comprising:
receiving a target image, wherein the target image corresponds to a target illuminated by an infrared light source during capture of the target by a camera sensitive to infrared light;
receiving a color image, the color image comprising a color image of a subject, the color image comprising a plurality of pixels;
generating a red channel image of the color image, the red channel image consisting substantially of a red component of each of the plurality of pixels in the color image; and
determining whether the target matches the subject by comparing the target image with the red channel image.
13. The method of claim 12 , wherein the color image of a subject comprises a color image of a known subject.
14. A method for comparing images, the method comprising:
receiving a target image, wherein the target image corresponds to a target illuminated by an infrared light source during capture of the target by a camera sensitive to infrared light;
receiving a color image, the color image comprising a color image of a subject, the color image comprising a plurality of pixels;
suppressing colors of shorter wavelengths in the color image to produce a color-suppressed image; and
determining whether the target matches the subject by comparing the target image with the color-suppressed image.
15. The method of claim 14 , wherein the infrared light source is an artificial light source.