Information processing apparatus, information processing method, and program

1. An information processing apparatus comprising:

a memory storing a set of instructions; and

one or more processors configured to execute the set of instructions to:

extract color information from a face image sequence;

determine temporal variations based on exactly two color components in the extracted color information; and

determine whether a face contained in the face image sequence is a spoofing based on the determined temporal variations.

2. The information processing apparatus according to claim 1 , wherein the one or more processor are configured to execute the set of instructions to:

determine that the face is a spoofing in response to determining that the temporal variations are not based on a human pulse.

3. The information processing apparatus according to claim 1 , wherein the color information includes a green color component and a blue color component.

4. The information processing apparatus according to claim 3 , wherein the color information includes, for each face image in the face image sequence, a first average value of the green color component and a second average value of the blue color component calculated across an entire portion of the face image.

5. The information processing apparatus according to claim 3 , wherein the color information includes, for each face image in the face image sequence, a first weighted average value of the green color component and a second weighted average value of the blue color component where the first and second weighted average values are calculated using weights assigned to facial parts contained in each face image.

6. The information processing apparatus according to claim 1 , wherein the one or more processor are further configured to execute the set of instructions to:

calculate at least one feature based on the determined temporal variations,

calculate a score by applying an evaluation function to the at least one feature, and

determine whether the face contained in the input face image sequence is a spoofing or not by comparing the score with a predetermined threshold.

7. The information processing apparatus according to claim 6 , wherein the at least one feature is a frequency spectrum of the determined temporal variations.

8. The information processing apparatus according to claim 7 , wherein the one or more processor are further configured to execute the set of instructions to calculate the score by calculating, for the frequency spectrum, a ratio between a total spectral intensity within a first frequency segment and a total spectral intensity within a second frequency segment.

9. An information processing method comprising:

extracting color information from a face image sequence;

determining temporal variations based on exactly two color components in the extracted color information; and

determining whether a face contained in the face image sequence is a spoofing based on the determined temporal variations.

10. The method according to claim 9 , wherein the face is determined to be a spoofing when the temporal variations are not based on a human pulse.

11. The method according to claim 9 , wherein the color information includes a green color component and a blue color component.

12. The method according to claim 11 , wherein the color information includes, for each face image in the face image sequence, a first average value of the green color component and a second average value of the blue color component calculated across an entire portion of the face image.

13. The method according to claim 11 , wherein the color information includes, for each face image in the face image sequence, a first weighted average value of the green color component and a second weighted average value of the blue color component where the first and second weighted average values are calculated using weights assigned to facial parts contained in each face image.

14. The method according to claim 9 , further comprising:

calculating at least one feature based on the determined temporal variations,

calculating a score by applying an evaluation function to the at least one feature, and

determining whether the face contained in the input face image sequence is a spoofing or not by comparing the score with a predetermined threshold.

15. The method according to claim 12 , wherein the at least one feature is a frequency spectrum of the determined temporal variations.

16. The method according to claim 15 , wherein the score is calculated by calculating, for the frequency spectrum, a ratio between a total spectral intensity within a first frequency segment and a total spectral intensity within a second frequency segment.

17. A non-transitory computer-readable storage medium storing instructions that when executed by a computer enable the computer to implement a method comprising:

extracting color information from a face image sequence;

determining temporal variations based on exactly two color components in the extracted color information; and

determining whether a face contained in the face image sequence is a spoofing based on the determined temporal variations.

18. The non-transitory computer-readable storage medium according to claim 17 , wherein the face is determined to be a spoofing when the temporal variations are not based on a human pulse.

19. The non-transitory computer-readable storage medium according to claim 17 , wherein the color information includes a green color component and a blue color component.

20. The non-transitory computer-readable storage medium according to claim 19 , wherein the color information includes, for each face image in the face image sequence, a first average value of the green color component and a second average value of the blue color component calculated across an entire portion of the face image.

21. The information processing apparatus according to claim 1 , wherein one of the exactly two color components is green.

22. The information processing apparatus according to claim 1 , wherein one of the exactly two color components is blue.

23. The information processing apparatus according to claim 1 , wherein the exactly two color components are green and blue.

24. The information processing apparatus according to claim 1 , wherein the temporal variations are further determined based on a first frequency spectral range corresponding to a human pulse, and a second frequency spectral range corresponding to noise components other than the pulse.