摘要
针对水下视觉测量中相机标定采集的水下标定图像退化造成标志点信息缺损的问题,提出了一种基于图像块分解融合的水下标定图像增强算法。首先,针对水下标定图像光照不均匀造成图像去雾困难的问题,基于同态滤波实现图像分割并计算全局背景光强,以实现图像去雾。然后,针对水下图像去雾后仍然存在噪声、模糊、光照不均匀等问题,分别进行对比度增强与细节信息增强以获得两幅互补增强图像,将互补图像划分成多个图像块,将图像块分解为平均强度、信号强度和信号结构3个独立分量,3个分量分开融合并求解最终增强图像。最后,采用主客观评价及标志点检测实验评价水下标定图像增强后的质量。实验结果表明,本文方法的视觉效果及客观评价得分均高于UDCP、MSR及ACDC方法,浑浊度为7.6NTU、11.4NTU、15.7NTU、18.4NTU时,标志点检测数量分别提高了2.0%、2.3%、9.3%、21.2%。因此,本文方法可以有效提高水下标定图像质量,为水下视觉测量提供一种稳定可靠的水下标定图像增强方法。
Aiming at the loss of target point information caused by the degradation of underwater calibration images collected by camera calibration in underwater visual measurement,an underwater calibration image enhancement algorithm based on image block decomposition and fusion is proposed.First,given the diffi-culty of image dehazing caused by uneven illumination of underwater calibration images,image segmenta-tion is implemented based on homomorphic filtering to calculate the global background light intensity and to achieve image dehazing.Then,given the problems such as noise,blur,and uneven illumination that still ex-ist after the underwater image is dehazed,contrast enhancement and detail information enhancement are per-formed to obtain two complementary enhanced images.The complementary images are divided into multiple image blocks,and the image blocks are decomposed into three independent components,each of which is av-erage intensity,signal intensity,and signal structure.The three components are separately fused and solved for the final enhanced image.Finally,subjective and objective evaluation and target point detection experi-ments are used to evaluate the enhanced quality of the underwater calibration image.Experimental results in-dicate that the visual effects and evaluation scores of the proposed method are higher than those of UDCP,MSR,and ACDC methods.When the turbidity is 7.6 NTU,11.4 NTU,15.7 NTU,and 18.4 NTU,the num-ber of detected target points increases by 2.0%,2.3%,9.3%,and 21.2%.Therefore,we present a reliable and effective method to improve the quality of underwater calibration images and provides a stable and reliable underwater calibration image enhancement method for underwater visual measurement.
作者
常志文
王立忠
梁晋
李壮壮
龚春园
巫志辉
徐建宁
CHANG Zhi-wen;WANG Li-zhong;LIANG Jin;LI Zhuang-zhuang;GONG Chun-yuan;WU Zhi-hui;XU Jian-ning(State Key Laboratory for Manufacturing Systems Engineering,College of Mechanical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《中国光学（中英文）》
EI
CAS
CSCD
北大核心
2024年第4期810-822,共13页
Chinese Optics
基金
国家重点研发计划项目(No.2022YFB4601802)
国家自然科学基金资助项目(No.52275543)。
关键词
图像块分解融合
水下图像增强
图像去雾
标志点
浑浊度
image block decomposition and fusion
underwater image enhancement
image defogging
tar-get point
turbidity
