红外焦平面阵列自适应数字化技术

Adaptive Digital Technique of IR FPA

针对红外焦平面阵列驱动电路固定A/D芯片模拟信号输入范围进行数字化、造成的红外图像细节分辨力低下的问题,提出了自适应的数字化技术,该技术消除了焦平面阵列的盲元干扰。根据进入焦平面的整体场景的灰度大小,设定适当的灰度阈值,计算出A/D转换芯片的偏置电压,自适应地调整模拟信号数字化范围,使焦平面的模拟输出数字化后最大限度地占据A/D芯片的数字位数。理论推导表明,该技术能够大幅度地提高红外图像的细节分辨力。

The universal digitalization method of the analog signal from infrared focal plane array （IR FPA） is that the drive board of IR PFA fixes the analog input range of analog-to-digital integrated circuit （A/D IC） and then converts it to the digital signal. This method results in the problem of low IR image resolution. In order to solve the problem, the adaptive digital technique was put forward, which obviates the blind pixel jamming of IR FPA. The gray threshold was set according to the whole scene gray, the bias voltage of A/D IC was calculated, the digital range of analog signal was adjusted adaptively, so as to make the output digital signal tranformed from the analog signal occupy more digital range of A/D IC. The theory derivation demonstrates that the technique can improve the IR image detail resolution by a big margin.