63×63 Gaussian-Radon filters at the directions of (a) 0°, (b) 30°, (c) 60°, (d) 90°, (e) 120°, and (f) 150°.

<p>63×63 Gaussian-Radon filters at the directions of (a) 0°, (b) 30°, (c) 60°, (d) 90°, (e) 120°, and (f) 150°.</p

The distribution of palm–vein images in six sub-classes by the proposed method in PolyU, CASIA, and the database of this study.

<p>The distribution of palm–vein images in six sub-classes by the proposed method in PolyU, CASIA, and the database of this study.</p

The rank-1 identification rate and EER by different methods using the CASIA database.

<p>The rank-1 identification rate and EER by different methods using the CASIA database.</p

The rank-1 identification rate [38] and EER by different methods using the PolyU database.

<p>The rank-1 identification rate <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112429#pone.0112429-PhillipsP1" target="_blank">[38]</a> and EER by different methods using the PolyU database.</p

Flowchart of the sub-classes construction.

<p>Flowchart of the sub-classes construction.</p

Flowchart of the system.

<p>Flowchart of the system.</p

The response time of identification process for one test sample by different coding methods at different database sizes.

<p>The response time of identification process for one test sample by different coding methods at different database sizes.</p

PRESS-localized single voxel 1H MR spectrum originating from liver parenchyma of the same ROI using body coil (a) and phased array coil (b); SNR: (b) was better than (a), so the score was marked 1.

<p>PRESS-localized single voxel 1H MR spectrum originating from liver parenchyma of the same ROI using body coil (a) and phased array coil (b); SNR: (b) was better than (a), so the score was marked 1.</p

Theoretical B₁ field distribution through the transverse planes centered at the ROI used for the calculation of SNR of different coils.

<p>The value of SNR was obtained when the mean B₁ value within the ROI was 1.957 μT. The SNR of body coil was normalized to 1 within the ROI for the transverse plane of body coil (a). The SNR of the transverse plane of phased array coil was 2.8387 (b). The results showed that the SNR of the phase array coil is higher than that of the body coil.</p

Palm–vein images at major directions of (a) 0°, (b) 30°, (c) 60°, (d) 90°, (e) 120°, and (f) 150° in PolyU, CASIA, and the database of this study.

<p>Palm–vein images at major directions of (a) 0°, (b) 30°, (c) 60°, (d) 90°, (e) 120°, and (f) 150° in PolyU, CASIA, and the database of this study.</p