用于标定CCD相机的高精度数控LED点光源

介绍了一种以发光二极管（LED）点光源作为相机标定光源的方法。根据LED点光源的特性，用恒流源给LED点光源提供所需的电流，用光照度计测量LED光源的光强度。由ARM单片下位机控制恒流源；通过串行通讯与上位机交换数据；由计算机作为上位机来管理数控恒流源和光照度计；根据所测光度值来调节电流，直到光度达到预想值。实验分析显示：LED点光源作为标定光源可以达到CCD标定的要求，精度也较高，能够很好地自适应控制LED的光照强度，达到了预期的效果，且系统使用方便灵活，性能稳定可靠。

High precision digital control LED spot light source used to calibrate CCD camera

This paper introduces a method that uses a Light Emitting Diode （LED） point light source as the camera calibration light. According to the characteristics of the LED point light source, a constant current source is used to provide the necessary current and a illuminometer is used to measure the luminance of the LED point light source. The constant current source is controlled by an ARM MCU and its data are exchanged with the host computer through the mode of serial communications. The PC is used as the host computer, and it adjusts the current according to the luminance of the LED point light source until the luminance achieves an anticipated value. Experimental analysis shows that the LED point light meet the requirements of the The system is convenient and calibration light source, and can adaptively flexible, and its performance is stable and source with a higher precision can control the luminance of LED well. reliable.