一种分焦平面偏振成像系统光源标定方法北大核心CSCD

水下偏振成像技术是目前水下成像研究的热点,由于自然光在水中衰减大,水下成像系统多采用主动照明方式。针对分焦平面偏振成像系统中偏振照明光源与偏振探测像元偏振方向不匹配引起采集图像偏振信息存在的偏差,进而影响目标图像增强质量的问题,提出了一种分焦平面偏振成像系统光源标定方法。阐述了偏振光源的标定原理,然后给出偏振光源标定的实施步骤,最后采用偏振去雾算法和图像质量评价方法对标定前后的水下目标图像进行了图像增强和图像质量评价。评价结果表明,标定后的增强图像质量优于未标定的增强图像质量,平均梯度最大提升了2.48倍。该标定方法简单有效,实用性强,适用于分焦平面偏振成像系统偏振光源标定。

Light source calibration for divided focal plane polarization imaging system

Polarization imaging technology under water is a hot spot in the research of underwater imaging. Due to the great attenuation of natural light in water, the underwater imaging system mostly adopts active illumination method. In order to solve the problem that the polarization information of acquired images was biased due to the mismatch of polarization direction between polarization illumination source and polarization detection element in divided focal plane polarization imaging system, which affected the quality enhancement of target images, a light source calibration method for divided focal plane polarization imaging system was proposed. First, the calibration principle of polarized light source was described, then the implementation steps of polarized light source calibration were given. Finally, the underwater target images before and after calibration were enhanced and the image quality was evaluated by using polarized dehazing algorithm and image quality evaluation method. The evaluation results show that the quality of the calibrated image restoration is better than that of the uncalibrated image restoration, and the average gradient can be improved by 2.48 times at most. The proposed calibration method is simple, effective and practical, which is suitable for the calibration of polarized light source in divided focal plane polarization imaging system.