Background Subtraction Method of TERS Topography Imaging Based on B-Spline
FAN Xian-guang1, WANG Xiao-dong1, WANG Xin1*, XU Ying-jie1, QUE Jing1, TANG Ming1, HE Hao1, ZUO Yong2
1. School of Aerospace Engineering, Xiamen University, Xiamen 361005, China
2. Changcheng Institute of Metrology & Measurement, The 1st Metrology & Measurement Research Center of National Defense Science Industry of China, Beijing 100095, China
Abstract：In the topography imaging of Tip-Enhanced Raman Spectroscopy, the difficulty of keeping the tip and the scan stage absolutely parallel, the fast change of the height of the tip due to the quick variety of the electron density, and the long response time of the scanning control system result in imaging background with inclined or boundary curly. Imaging background would bring a negative impact to the identification and analysis of the sample’s topographic image，while background subtraction is an important means to solve this problem, which is also an important part of topographic image’s preprocessing. The general principle of background subtraction is to fit the topographic image’s background firstly and then subtract it from the image. The traditional fitting method is polynomial fitting line by line, but this method will always destroy the sample’s actual spatial topography by over-fitting, and it is prone to leave clear line texture on the image. In this paper, the traditional method was improved, and the B-spline surface fitting method was used to approach the background of topographic image through constant iteration. The advantage of B-spline surface, namely low-order and smoothness, can help the method overcome the disadvantages of traditional polynomial method. In the experiments, the topographic image of Au (111) single-crystal and synthetic golden slice were detected, and then the proposed method and the traditional method were applied to perform background subtraction. Experimental results showed that the proposed method can eliminate the topographic image’s background effectively without destroying the sample’s actual spatial topography by over-fitting and leaving line texture on the image. Therefore, the proposed method provided more accurate and reliable information for the further analysis of topographic images, and it’s a more effective background subtraction method of TERS topography imaging.
范贤光，王小东，王 昕，许英杰，阙 靖，汤 明，何 浩，左 勇. 基于B样条的TERS形貌成像背景扣除方法[J]. 光谱学与光谱分析, 2018, 38(02): 394-400.
FAN Xian-guang, WANG Xiao-dong, WANG Xin, XU Ying-jie, QUE Jing, TANG Ming, HE Hao, ZUO Yong. Background Subtraction Method of TERS Topography Imaging Based on B-Spline. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(02): 394-400.
