基于图像灰度的大范围辐射温度反演

为解决高温辐射源和环境温度对红外测温的影响,提高极端工况下红外热像仪的测温精度,以红外辐射理论以及红外热像仪测温原理为基础,提出了一种将红外图像灰度与目标温度、环境温度和积分时间相结合的综合辐射温度反演方法,该方法实现了环境(镜头)温度与场景温度参量解耦,可以独立预估各参量变化所产生的探测器响应变化。首先对红外热像仪进行数据标定,标定时一般采用高精度面源黑体,之后通过计算面源黑体辐射亮度,利用黑体辐亮度和黑体灰度的线性关系,对黑体温度与黑体图像灰度值两组数据之间关系进行拟合,建立全环境温度和全积分时间的大范围温度反演匹配模型。最后在实验室环境下,分别用热像仪和基于灰度的温度反演模型对探测目标进行测温。经过实验验证,该反演模型在实验室环境下取得了较为良好的效果。

Temperature inversion of high temperature radiation source based on image gray value

Based on infrared radiation theory and infrared thermal imager temperature measurement principle,a comprehensive radiation temperature inversion method combining infrared image gray level with target temperature,environment temperature and integral time is proposed to solve the influence of high temperature radiation source and environment temperature on infrared temperature measurement,and improve the temperature measurement accuracy of infrared thermal imager under extreme working conditions.This method realizes the decoupling of ambient(lens)temperature and scene temperature parameters,and can independently predict the changes of detector response caused by the changes of each parameter.Firstly,the data calibration of infrared thermal imager is carried out,in which high precision surface source blackbody is generally adopted.Then,by calculating the radiation luminance of surface source blackbody and using the linear relationship between blackbody radiance and blackbody gray,the relationship between blackbody temperature and the gray value of blackbody image is fitted,and a large range temperature inversion matching model of the whole ambient temperature and the whole integral time is established.Finally,in the laboratory environment,the thermal imager and the temperature inversion model based on gray level are respectively used to measure the temperature of the detected target.The experimental results show that the inversion model achieves relatively good results in laboratory environment.