红外硫系玻璃透射率高,光谱范围宽,可广泛应用于红外热像仪等光学系统,然而红外玻璃在熔制过程中容易因组分不均匀造成各种内部缺陷,影响成像质量。利用透视成像的原理,在分辨力估算的基础上,设计了一种可检测玻璃内部宏观缺陷的系统。这种系统光源功率可调,可以检测厚度和直径都在几毫米到几十毫米范围内的红外硫系玻璃,在300mm成像距离条件下分辨尺寸达到0.19mm,并且可对长度63.4mm的物体成满像。通过Sobel算子进行玻璃内部条纹边缘提取,可以获得更加清晰的条纹特征。
Chalcogenide glasses are widely used in optical systems of thermal imagers for its high transmission and broad spectral band width.However,internal defects brought by composition's disproportion of glasses during the melting and solidification can affect the imaging performance.A detection system of internal macroscopic defects is introduced by using the principle of perspective imaging based on resolution estimate.The optical power of system is adjustable,which can detect the thickness and diameter of glass samples within several millimeters to dozens of millimeters.It's resolution can reach 0.19 mm at the distance of 300 mm,and it can make a full image of an object at 63.4 mm.The distinct stripes inside the glasses are obtained by glass edge extration of internal stripe through Sobel operator.