非致冷红外焦平面阵列(IRFPA)固有的非均匀性严重制约了系统成像质量, 其输出动态范围大和监视器显示输出动态范围小也构成了矛盾。为解决这些问题, 采用了复杂可编程逻辑器件(CPLD)设计红外焦平面阵列输出驱动和视频编码芯片的显示时序, 以高速低功耗数字信号处理器(DSP)为核心, 实现了嵌入式红外图像实时采集与压缩校正硬件系统。提出了一种结合两点校正的灰度直方图统计阈值分段线性压缩变换算法, 并进行了实验。结果表明, 系统可以实时的对红外图像进行采集和压缩校正, 处理后图像的非均匀性得到很好的校正, 背景被抑制的同时目标和细节得到了增强。该方案简单可靠, 电路功耗较低, 可为小型化红外热像仪的研制提供参考。

The inherent nonuniformity of the uncooled infrared focal plane arrays (IRFPA) crucially limits its imaging quality, and there is also a contradiction between the wide dynamic range of infrared source and the small of it for display. To solve these problems, the embedded infrared image real-time processing hardware system is designed which adopts a complex programmable logic device (CPLD) to drive the timing sequence of IRFPA and video encoder, with a core of high-speed and low power consumption digital signal processor (DSP). Combination with two-point correction, a segmentation gray scale compressing transform method based on histogram statistics threshold is proposed and experimented. The results prove that the image can be captured and processed real-timely, the processed image is corrected effectively, and the background is suppressed while the target and details are enhanced. The proposed scheme with simple architecture, high reliability and low power consumption characters can provide a valuable reference for the development of miniaturized thermal infrared imager.