CAJ | 학술논문

针对用于目标跟踪的大视场CCD相机的特殊结构,为了获得高质量图像,提出了一种基于电子快门无级调节的自动调光方法,即通过实时调整CCD相机的曝光时间来实现快速、高精度调光.文中提出了多区域灰度加权的图像灰度均值提取方法,消除了因大视场CCD相机背景图像数据过多而给自动调光带来的影响.系统采用FPGA内置RAM,通过乒乓缓存策略保证调光算法的实时性.通过对CCD相机的辐射定标和外景成像实验表明:该调光方法在辐亮度为25.697~260.548 W/m~2·sr区间内具有良好的图像质量,不仅满足调光速度快、实时性好、适应性强的要求,而且与无调光模式工作状态比较,CCD相机的动态范围增大了20倍,满足调光范围宽的要求.
침대용우목표근종적대시장CCD상궤적특수결구,위료획득고질량도상,제출료일충기우전자쾌문무급조절적자동조광방법,즉통과실시조정CCD상궤적폭광시간래실현쾌속、고정도조광.문중제출료다구역회도가권적도상회도균치제취방법,소제료인대시장CCD상궤배경도상수거과다이급자동조광대래적영향.계통채용FPGA내치RAM,통과핑퐁완존책략보증조광산법적실시성.통과대CCD상궤적복사정표화외경성상실험표명:해조광방법재복량도위25.697~260.548 W/m~2·sr구간내구유량호적도상질량,불부만족조광속도쾌、실시성호、괄응성강적요구,이차여무조광모식공작상태비교,CCD상궤적동태범위증대료20배,만족조광범위관적요구.
According to the special structure of the large visual field CCD camera used in moving target tacking, a new method based on adjusting the electronic shutter steplessly is proposed to get the high quality image. Through adjusting the exposal time in real time, we could make the light adjusting fast and accurately. To draw the gray scale of the image, this paper put forward a new method named the gray scale weighting of different regional. Since the large visual field CCD camera has a lot of background image data, it will bring much influence to the auto light control. The new gray scale drawing method which is advanced in writing could eliminate the influence. Using the RAM of FPGA, the system ensured that the light-adjusting arithmetic could work in real time by the ping-pang buffer usage strategy. The radiation scale and the result of location experiment indicated that the method could offer best image quality when the radiant luminance is from 25 W/m~2·sr to 260 W/m~2·sr.The dynamic range of the new system had increased 20 times compared with that of the system without the auto light control. The new method satisfied not only the requirment of the wide dynamic range, but also the fast speed, the real-time, and the good adaptability.