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Scattering removal for finger-vein image restoration.

Yang J, Zhang B, Shi Y - Sensors (Basel) (2012)

Bottom Line: To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues.Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration.Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy.

View Article: PubMed Central - PubMed

Affiliation: Tianjin Key Laboratory for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300, China. jfyang@cauc.edu.cn

ABSTRACT
Finger-vein recognition has received increased attention recently. However, the finger-vein images are always captured in poor quality. This certainly makes finger-vein feature representation unreliable, and further impairs the accuracy of finger-vein recognition. In this paper, we first give an analysis of the intrinsic factors causing finger-vein image degradation, and then propose a simple but effective image restoration method based on scattering removal. To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues. Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration. Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy.

Show MeSH
Image contrast reduction due to light scattering. (a) A real shadow as no light scattering. (b) A degraded shadow as light scattering.
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f2-sensors-12-03627: Image contrast reduction due to light scattering. (a) A real shadow as no light scattering. (b) A degraded shadow as light scattering.

Mentions: Generally, in order to visualize finger-vein vessels inside the finger tissues, the near infrared (NIR) transillumination is often adopted in imaging devices, as shown in Figure 1(a,b). As the hemoglobin in blood vessels absorbs more NIR radiation than other substances in finger tissues [1], the intensity distribution of transmitted NIR rays vary spatially. Vein vessels cast darker “shadows” on imaging plane while other tissues present a brighter background, as shown in Figure 1(c). Since the biological tissues can be viewed as a kind of highly heterogeneous optical medium, multiple light scattering predominates in lights that penetrate through a biological tissue layer [2]. Thus, the quality of finger-vein images is always poor because the scattering effects can greatly reduce the contrast between the venous and non-venous regions [3]. The basic concept of image degradation due to light scattering is illustrated in Figure 2. If no light scattering is generated in optical medium, a real shadow of an object must appear on the imaging plane, as shown in Figure 2(a). However, the object shadow always is blurred to a certain extent since light scattering is inevitable in real situations, as shown in Figure 2(b).


Scattering removal for finger-vein image restoration.

Yang J, Zhang B, Shi Y - Sensors (Basel) (2012)

Image contrast reduction due to light scattering. (a) A real shadow as no light scattering. (b) A degraded shadow as light scattering.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376557&req=5

f2-sensors-12-03627: Image contrast reduction due to light scattering. (a) A real shadow as no light scattering. (b) A degraded shadow as light scattering.
Mentions: Generally, in order to visualize finger-vein vessels inside the finger tissues, the near infrared (NIR) transillumination is often adopted in imaging devices, as shown in Figure 1(a,b). As the hemoglobin in blood vessels absorbs more NIR radiation than other substances in finger tissues [1], the intensity distribution of transmitted NIR rays vary spatially. Vein vessels cast darker “shadows” on imaging plane while other tissues present a brighter background, as shown in Figure 1(c). Since the biological tissues can be viewed as a kind of highly heterogeneous optical medium, multiple light scattering predominates in lights that penetrate through a biological tissue layer [2]. Thus, the quality of finger-vein images is always poor because the scattering effects can greatly reduce the contrast between the venous and non-venous regions [3]. The basic concept of image degradation due to light scattering is illustrated in Figure 2. If no light scattering is generated in optical medium, a real shadow of an object must appear on the imaging plane, as shown in Figure 2(a). However, the object shadow always is blurred to a certain extent since light scattering is inevitable in real situations, as shown in Figure 2(b).

Bottom Line: To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues.Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration.Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy.

View Article: PubMed Central - PubMed

Affiliation: Tianjin Key Laboratory for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300, China. jfyang@cauc.edu.cn

ABSTRACT
Finger-vein recognition has received increased attention recently. However, the finger-vein images are always captured in poor quality. This certainly makes finger-vein feature representation unreliable, and further impairs the accuracy of finger-vein recognition. In this paper, we first give an analysis of the intrinsic factors causing finger-vein image degradation, and then propose a simple but effective image restoration method based on scattering removal. To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues. Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration. Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy.

Show MeSH