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(b) 0.27/0.24
0.29/0.30

(c) 0.22/0.24
0.24/0.24

(d) 0.23/0.25
0.24/0.27

(e) 0.27/0.24
0.29/0.31

(f) 0.22/0.19
0.20/0.25

(g) 0.27/0.34
0.28/0.26

(a)

Figure 17. Some examples in typical scenes. (a) Ideal experimental environment;
(b–d) indoor scenes under different illumination; (e) scene under direct sunlight; (f) scene
under side light; (g) scene under non-uniform illumination and shadow. The four values
under each image indicate the matching distances of the four IKP ROIs against (a),
respectively. The threshold applied here is 0.41, the same as in Figure 14.
6.3.4. Time Performance
We implement our system, as well as the other four competitors on a PC with Intel Core i7 4790 K
4.4 GHz CPU with eight threads, 16 GB RAM and the Microsoft Windows 7 64-bit operating system.
Table 1 shows that all of the methods achieve high efficiency, although our method is a little slower than
the others. Meanwhile, our method can maintain high efficiency even under an enormous database, since
the features of the training images are extracted offline and only the matching algorithm is computed
online, which is so efficient due to parallel computation (generally < 50 ms for one thousand times).
7. Conclusions
We propose a robust IKP matching and identification method for biometric authentication purposes.
The proposed method can survive under uncontrolled lighting conditions, noisy and blurry image
acquisition, as well as deformation due to hand orientation and perspective projection. Hence, users

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of the biometric authentication system can be relieved from the careful planning of the acquisition
environment and the unnatural hand orientation during the capture. The proposed method outperforms
state-of-the-art biometric feature recognition methods when the acquisition environment is challenging.

Let me help create a natural query based on this text:

### Language ###
English

### Assessment ###
The text contains information about processing time performance of a biometric system on specific computer hardware.

### Query ###
What CPU was used to test the IKP matching system?

(This is a natural query someone might ask when researching biometric system implementations, and the text clearly states it was an "Intel Core i7 4790 K 4.4 GHz CPU")
What CPU was used to test the IKP matching system?

(This is a natural query someone might ask when researching biometric system implementations, and the text clearly states it was an "Intel Core i7 4790 K 4.4 GHz CPU")