舰船尾迹图像的对比度特征提取方法

摘要

It is an essential fundamental to evaluate the ship wake image's quality quantitatively and effec-tively,and to achieve the extraction of ship wake's optical signal characteristics rapidly in today's ship op-tics-wake elimination technologies. The method regarding quality evaluation of ship wake images is stud-ied in this paper based on the contrast model. By analyzing the characteristics of the obvious contrast be-tween the wake area and the seawater background area in ship wake images,this paper uses the contrast parameter as an critical index for the wake image quality evaluation process as well as the characterization of ship wake's optical signal characteristical strength. Specifically,in order to evaluate the actual quality of ship wake images,the weighting factors on both wake areas and seawater background areas are intro-duced,and the basic contrast calculation model is improved. This model fully considers the human visual characteristics and combines the subjective and objective evaluation methods comprehensively. A corre-sponding experiment is also conducted,which particularly focuses the maritime feature extraction. The re-sults show that the contrast parameters do not only reflect the subjective visual perception of human eyes on the wake images' actual quality,but also better reflect the application essence of the wake image pro-cessing. In brief,the contrast parameters reliably and quantitatively describe the intensity's changing rules of the ship wake's optical signal characteristics.%根据舰船尾迹图像尾迹区与海水背景区存在明显对照的特性，提出用对比度参数作为尾迹图像质量评价指标，进而表征舰船尾迹光学信号特征强度。为有效评价尾迹图像质量，在改进对比度基本计算模型的基础上，充分考虑人的视觉特性，引入尾迹区与海水背景区的加权因子进行组合评价，将主观与客观评价方法有机结合起来，并通过专门研制的海上特征提取实验装置进行对比度特征提取实验分析。结果表明，对比度参数能较好地反映人眼对尾迹图像实际质量的主观视觉感受，更能体现尾迹图像处理应用的本质，且能定量可靠地描述舰船尾迹光学信号特征强度的变化规律。