﻿ 基于FPGA的静脉图像双边滤波算法 Bilateral Filter Algorithm of Vein Image Based on FPGA

Journal of Image and Signal Processing
Vol. 08  No. 03 ( 2019 ), Article ID: 31156 , 6 pages
10.12677/JISP.2019.83018

Bilateral Filter Algorithm of Vein Image Based on FPGA

Yueqing Liang, Xiaoyu Cui*

Sino-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang Liaoning

Received: Jun. 12nd, 2019; accepted: Jun. 29th, 2019; published: Jul. 5th, 2019

ABSTRACT

The bilateral filter algorithm reduces noise in hand vein image while preserving edge details of vein. By implementing the bilateral filter algorithm on FPGA, features of FPGA such as parallel and pipeline processing can boost the calculation speed of the algorithm. While satisfying the real-time requirements of hand vein imaging system, this implementation can enhance the hand vein image for subsequent segmentation and extraction of vein.

Keywords:Bilateral Filter, FPGA, Hand Vein, Image Processing

1. 引言

2. 双边滤波算法

$\stackrel{¯}{\varphi }\left(\stackrel{¯}{{m}_{0}}\right)=\frac{1}{k\left({m}_{0}\right)}{\sum }_{m\in F}\varphi \left(m\right)\cdot s\left(\varphi \left({m}_{0}\right),\varphi \left(m\right)\right)\cdot c\left({m}_{0},m\right)$ (1)

$s\left(\varphi \left({m}_{0}\right),\varphi \left(m\right)\right)={e}^{-\frac{1}{2}{\left(\frac{‖\varphi \left({m}_{0}\right)-\varphi \left(m\right)‖}{{\sigma }_{ph}}\right)}^{2}}$ (2)

$c\left({m}_{0},m\right)={e}^{-\frac{1}{2}{\left(\frac{‖{m}_{0}-m‖}{{\sigma }_{c}}\right)}^{2}}$ (3)

$k\left({m}_{0}\right)={\sum }_{m\in F}S\left(\varphi \left({m}_{0}\right),\varphi \left(m\right)\right)\cdot c\left({m}_{0},m\right)$ (4)

3. 双边滤波算法的FPGA实现

3.1. 双边滤波处理步骤

Figure 1. Flow chart of algorithm process

3.2. 亮度相似度权重系数计算

1) 像素值的位宽N；

2) 参数σph

3) 权重系数的位宽W；

Figure 2. Limitation of the number of weight coefficient

Figure 3. Brightness similarity operato

3.3. 空间邻近度权重系数计算

3.4. 归一化

Figure 4. Spatial proximity operator

Figure 6. Normalization of weight pixel value

4. 实验结果

Figure 7. Images filtered by bilateral filter and gauss filter

5. 结论

Bilateral Filter Algorithm of Vein Image Based on FPGA[J]. 图像与信号处理, 2019, 08(03): 130-135. https://doi.org/10.12677/JISP.2019.83018

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6. NOTES

*通讯作者。