凝视热成像系统的三角方向鉴别阈值曲线预测

Triangle Orientation Discrimination Threshold Curve Prediction Based on Staring Thermal Imaging Simulation

为有效评价凝视成像系统的性能,依据凝视红外成像系统对红外辐射信号的转换机理,建立了凝视红外成像系统信号响应模型;利用线性系统理论和采样理论对成像系统的传递函数进行了分析建模;借助于三维噪声模型表征了系统的噪声特性。以成像系统建模为基础,模拟生成不同尺寸、不同辐射温差的等边三角形方位靶标图像;针对不同刺激强度的三角形靶标仿真图像,统计观察者对靶标方向正确鉴别的概率,引入视觉心理测量函数———韦布尔(Weibull)函数拟合观察者鉴别概率数据,实现了三角方向鉴别阈值(TOD)曲线的预测。与实际测量结果进行比较,显示了此方法预测三角方向鉴别阈值曲线的合理性。

For the effective performance evaluation of staring imaging system, the signal response model of staring imaging system is established according to the conversion mechanism of infrared radiometric signal in the imaging process. The transfer function of imaging system is modeled using the linear system theory and sampling theory, and the noise is characterized with the three-dimensional noise model. Based on staring imaging system modeling, the triangle pattern simulation images with different differential temperatures and different sizes are generated. Triangle pattern simulation images with different stimulus intensities are observed, and the correct discrimination probability of the triangle pattern orientation is obtained utilizing the statistical method. The psychometric function-Weibull function is used to fit the probability data, and the triangle orientation discrimination （TOD） threshold prediction curve is achieved. The experimental results indicate that the triangle orientation discrimination threshold prediction curve is reasonable.