中文摘要：

基于CCD的火焰图像监控技术是锅炉燃烧控制的研究热点,该方法的关键环节是获取清晰可靠的火焰彩色图像。针对这一需求,本文采用小波分析双阈值法对火焰彩色图像进行增强,首先将彩色图像分解成RGB三个二维信号,再分别对其进行小波变换,将得到的小波系数采用双阈值法进行提升和缩小以达到增强和去噪的目的,再进行小波重构,之后将新的RGB二维信号重新组合得到增强后的彩色火焰图像。实验表明：采用该方法增强后,图像层次感较强,细节突出,火焰各燃烧区域区分明显;二维温度场测量精度提高了0.62%,绝对误差降低了5.3℃,有利于改善整个锅炉燃烧系统的控制性能。

英文摘要：

The flame image monitoring technology based on CCD is a research focus of the boiler combustion control,and the key of this method is to obtain a clear and reliable flame color image.In response to this demand,wavelet analysis and dual-threshold method are used to enhance flame color image.Firstly,the color image is decomposed into three two-dimensional RGB signals.Secondly,the RGB signals are processed through wavelet transform respectively,and those wavelet coefficients are amplified and reduced using dual-threshold method for the purpose of enhancement and denoising.Then,the new RGB signals are reconstructed by those wavelet coefficients.At last,the new RGB signals are regrouped to get enhanced flame color image.Experimental results show that,after processed by this method,the image has a strong sense of hierarchy,detail of image is outstanding and the distinction of the combustion zone of the flame is obvious.Moreover,measurement precision of two-dimensional temperature field is improved by 0.62% and the absolute error is reduced by 5.3℃.This is helpful to improve the performance of the boiler combustion control system.