原木横截面CT图像的伪彩色增强方法对比研究  

Comparative Study of Pseudo Color Enhancement Method to Log Cross Section CT Images

作　　者：周涵婷 徐华东[1] 曹延珺 徐群 狄亚楠 Zhou Hanting;Xu Huadong;Cao Yanjun;Xu Qun;Di Yanan(College of Engineering and Technology,Northeast Forestry University,Harbin 150040)

机构地区：[1]东北林业大学工程技术学院,哈尔滨150040

出　　处：《森林工程》2018年第4期57-62,共6页Forest Engineering

基　　金：哈尔滨市应用技术研究与开发项目(2017RAQXJ078);国家自然科学基金项目(31300474)

摘　　要：CT灰度图像具有分辨率低,不利于人眼直观分析等不足,而CT图像直观分析是最基本的CT分析方法。为提高原木CT图像的分辨率,利用在不同温度(15、-5、-20℃)下扫描获取的杉木、红松和冷杉三个树种原木横截面CT图像,采用灰度级-彩色变换方法,通过彩虹码和热金属码的编码方法实现图像伪彩色增强,并对两种方法在不同温度下CT图像的增强效果和特征进行对比分析。研究表明:(1)伪彩色增强方法能显著提高CT图像的视觉分辨率,减少直观判断误差。如视觉灰度相近的A与B两处(CT值范围分别为-550^-680Hu和-530^-730Hu)在不同方法的增强图像中呈现出不同的颜色差异。(2)热金属码的视觉增强效果低于彩虹码。彩虹码能为CT图像直观分析提供更多的细观物理信息,而热金属码能更加明确、清晰地划分出木材内部不同密度的结构分布。(3)相较于CT灰度图像,伪彩色增强后的图像有利于研究不同温度下木材内部结构、各相组分的变化情况,为定量研究温度对木材内部水分的状态和含量变化提供新的思路。CT gray image has low resolution and is not conducive to human visual analysis, but CT image intuitive analysis is the basic method of CT analysis. In order to improve the log CT image resolution, using cross section CT images of Cunninghamia lanceolata, Pinus koraiensis and Abies fabriat obtained by scanning at different temperatures （15, -5, -20^1 ）, applying the gray- color transform method, image pseudo color enhancement based on rainbow code and hot metal code is implemented. Then, the enhancements and characteristics of two methods for CT images at different temperatures are compared and analyzed. Research shows that： ？ Pseudo color enhancement method can significantly improve the image resolution, reduce visual intuitive judgment error. Such as A and B with similar visual intensity （the ranges of CT values respectively are 550 ~ -680Hu and -530 ~ -730Hu） in different pseudo color enhancement method of showing a different color difference image. （2） The visual enhancement effect of hot metal code is lower than that of rainbow code. Rainbow code can provide more information for intuitive analysis of CT image, and hot metal code can more clearly divide the structure distribution of different density inside the log. ？ Pseudo color enhancement method is helpful to study the change of internal structure and components, providing a new idea for quantitative study about the change of wood interior water in the state and content at different temperatures.

关 键 词：原木 计算机断层扫描CT图像 视觉分辨率 灰度级-彩色变换法 伪彩色增强 

分 类 号：S781.5[农业科学—木材科学与技术]