|
|
|
|
|
|
Based on Double Threshold Canny Equalization Algorithm for Terahertz Image Enhancement |
SHI Ye-xin, LI Jiu-sheng* |
Center for Terahertz Research Institute in China Jiliang University, Hangzhou 310018, China |
|
|
Abstract Terahertz wave (THz), which exists between microwave and far infrared, has made the terahertz spectroscopy and imaging technology develop rapidly in recent years because of its non-damage property and high stability. The unique feature of non-invasive detection of terahertz wave has a perfect prospect in the field of security detection, and has attracted the attention of scholars. Although THz images obtained by terahertz imaging system can identify hidden weapons or other metal products, the THz image contrast and clarity are poor, which can not completely accord with human visual effect, and is not conducive to machine recognition. At present, the enhancement and improvement of terahertz image quality are the key to the long-term development and wide application of THz imaging technology. By using terahertz projection imaging system with scanning step 0.5mm, we imagine the objects of the metal pendant and metal arrow hidden in clothes at the same experimental conditions. Because of the system defects such as terahertz light source, energy fluctuation as well as the complexity and interference of the external environment, the imaging of the imaging system we get has serious background noise and blurred boundary, and the imaging quality is poor. This paper presents an algorithm of Canny equalization based on double threshold for THz image enhancement. According to the property limitations of terahertz image itself, this algorithm determines the relevant thresholds and the range of image equalization to realize the image denoising. The algorithm introduces the double threshold Canny algorithm and the gradient amplitude algorithm to improve the contrast and clarity of the image, preserve and highlight the detail information of the terahertz image, as well as obtain the high resolution and clear edge image. The experimental results show that we successfully obtain the terahertz images with improved definition, lower noise and fully detailed information from tow low-resolution (LR) terahertz images. The quality of images is improved.This work also enhances the discrimination ability and perspective capability for the hidden defects or hidden objects in the terahertz images, which demonstrates the enormous potential that the terahertz imaging provides the application in the security check.
|
Received: 2017-07-17
Accepted: 2017-11-30
|
|
Corresponding Authors:
LI Jiu-sheng
E-mail: lijsh@126.com
|
|
[1] CHEN Tao, LI Zhi, MO Mei, et al(陈 涛,李 智,莫 玮,等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2014, 34(12): 3241.
[2] Zhang P, Li F. IEEE Signal Processing Letters, 2014, 21(10): 1280.
[3] Zhong H, Li Y, Jiao L C. IEEE Geoscience and Remote Sensing Letters, 2011, 8(4): 809.
[4] Wang J, Guo Y, Ying Y, et al. IEEEInternational Conference on Image Processing (ICIP), 2006, 1: 1429.
[5] Dong Y, Li M, Li J. Electric Engineering and Computer (MEC), 2013, 1: 1453.
[6] Liu H, Yao J, Wang Y, et al. Journal of Infrared and Millimeter Waves, 2016, 3(35): 299.
[7] Bao Y, Wu D. International Conference on Manufacturing Science and Engineering, 2016, 32: 423.
[8] Alvydas L, Maris B, Sebastian B, et al. J. Infrared Millimeter and Terahertz Waves, 2014, 35(1): 63.
[9] Bhatt U, Singh A, Bhadauria H, et al. Inventive Computation Technologies, 2016, 3: 1.
[10] Xiang H, Hong L. Computer Science & Service System, 2012, 1: 250.
[11] Miaomiao Z, Hongxia L, Yi W. Progress in Informatics and Computing, 2015, 1: 234. |
[1] |
ZHU Yan-ping1, CUI Chuan-jin1*, CHENG Peng-fei1, 2, PAN Jin-yan1, SU Hao1, 2, ZHANG Yi1. Measurement of Oil Pollutants by Three-Dimensional Fluorescence
Spectroscopy Combined With BP Neural Network and SWATLD[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(08): 2467-2475. |
[2] |
CHU Zhi-hong1, 2, ZHANG Yi-zhu2, QU Qiu-hong3, ZHAO Jin-wu1, 2, HE Ming-xia1, 2*. Terahertz Spectral Imaging With High Spatial Resolution and High
Visibility[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(02): 356-362. |
[3] |
YANG Hua-dong1, 2, ZHU Hao1, 2, WANG Zi-chao1, 2, LIU Zhi-ang1, 2. Research on On-Line Monitoring Technology of Water Sediment
Concentration Based on Transmission Spectrum[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(12): 3817-3822. |
[4] |
WANG Zhong, WAN Dong-dong, SHAN Chuang, LI Yue-e, ZHOU Qing-guo*. A Denoising Method Based on Back Propagation Neural Network for
Raman Spectrum[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(05): 1553-1560. |
[5] |
ZHU Hong-qiu1, CHENG Fei1, HU Hao-nan1, ZHOU Can1, 2*, LI Yong-gang1. Denoising Algorithm of Spectral Signal Based on FFT SVD[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(01): 277-281. |
[6] |
JIAO Qing-liang1, LIU Ming1*, YU Kun2, LIU Zi-long2, 3, KONG Ling-qin1, HUI Mei1, DONG Li-quan1, ZHAO Yue-jin1. Spectral Pre-Processing Based on Convolutional Neural Network[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(01): 292-297. |
[7] |
WANG Zi-jun1, 2, LUO Yuan-yi1, 2*, JIANG Shang-zhi1, 2, XIONG Nan-fei1, 2, WAN Li-tao1, 2. An Improved Algorithm for Adaptive Infrared Image Enhancement Based on Guided Filtering[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(11): 3463-3467. |
[8] |
FAN Xian-guang1, 2, 3, WU Teng-da1, ZHI Yu-liang1, WANG Xin1, 2, 3*. Denoising Method for Raman Imaging Data Based on Singular Value Decomposition and Median Absolute Deviation[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(02): 436-440. |
[9] |
ZHENG Guo-liang, ZHU Hong-qiu*, LI Yong-gang. Spectral Signal Denoising Algorithm Based on Improved LMS[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(02): 643-649. |
[10] |
ZHANG Tian-tian1, LI Bing2*, CAI Gui-min2, LI Jun-hui1*, MA Yan-jun3, MA Li3, ZHAO Long-lian1, WU Shu-en2. Study on Spectral Data Processing Methods of New Type High-Density Grating Spectrometer Made in China[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(08): 2651-2656. |
[11] |
QIU Xuan-bing1, SUN Dong-yuan1, LI Chuan-liang1*, WU Ying-fa1, ZHANG En-hua1, WEI Ji-lin1, WANG Gao2*, YAN Yu3*. Wavelet Denoising Research for the Tunable Laser Diode Absorption Spectroscopy of the CO at 1.578 μm[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(02): 628-633. |
[12] |
ZHAO Xiao-yu1, HE Yan1, ZHAI Zhe2, TONG Liang3, CAI Li-jing1, SHANG Ting-yi1. LCEEMD Adaptive Denosing Method for Raman Spectra with Low SNR[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(10): 3124-3128. |
[13] |
JU Wei1,LU Chang-hua1, 2,ZHANG Yu-jun2,JIANG Wei-wei1,WANG Ji-zhou1,LU Yi-bing2. Open-Path Fourier Transform Infrared Spectrum De-Noising Based on Improved Threshold Lifting Wavelet Transform and Adaptive Filter[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(06): 1684-1690. |
[14] |
LI Ying1, LI Yao-xiang1*, LI Wen-bin2, JIANG Li-chun3. Model Optimization of Wood Property and Quality Tracing Based on Wavelet Transform and NIR Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(05): 1384-1392. |
[15] |
ZHAO Ming-fu1, 2, TANG Ping1, 2, TANG Bin1, 2, 3*, HE Peng3, XU Yang-fei1, 2, DENG Si-xing1, 2, SHI Sheng-hui1, 2. Research on Denoising of UV-Vis Spectral Data for Water Quality Detection with Compressed Sensing Theory Based on Wavelet Transform[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(03): 844-850. |
|
|
|
|