基于Shearlet域的改进加权法结合自适应PCNN的图像融合算法  

Image Fusion Algorithm Based on Improved Weighted Method and Adaptive Pulse Coupled Neural Network in Shearlet Domain

作　　者：王英[1] 刘帆 陈泽华 WANG Ying;LIU Fan;CHEN Ze-hua(College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,China;College of Big Data,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学电气与动力工程学院,太原030024 [2]太原理工大学大数据学院,太原030024

出　　处：《计算机科学》2019年第4期261-267,共7页Computer Science

基　　金：国家自然科学基金项目(61402319;61403273;61703299);山西省自然科学基金项目(201601D202044)资助

摘　　要：针对传统多聚焦图像融合算法获得的融合图像对比度低的问题,提出基于改进加权法和自适应脉冲耦合神经网络的多聚焦图像融合算法。首先,源图像经Shearlet分解产生一个低频子带和一系列不同尺度、不同方向的高频子带。将源图像的低频子带的和以及低频子带的差的绝对值进行加权求和,采用平均梯度计算权值,得到融合后的低频子带;高频子带采用自适应脉冲耦合神经网络融合规则,其中,脉冲耦合神经网络采用改进的拉普拉斯能量和作为激励,其链接强度由源图像的区域空间频率自适应计算,根据脉冲耦合神经网络的点火映射图得到融合后的高频子带,最后经Shearlet逆变换得到融合图像。文中选择1组人工仿真多聚焦图像Cameraman和3组真实的多聚焦图像Pepsi,Clock和Peppers进行实验,并与其他7种融合方法进行比较,采用4种常见的质量评价指标对融合图像进行客观评价。实验结果表明,所提方法在主观视觉和客观评价上均有较好的效果。Since traditional multi-focus image fusion algorithm has the problem of low contrast ratio,this paper presented a multi-focus image fusion algorithm based on improved weighted method and adaptive pulse coupled neural network (PCNN) in Shearlet domain.Firstly,the source images are decomposed by Shearlet transform to generate a low-frequency subband and a series of high-frequency subbands with different scales in different directions,then the weighted sum of the low-frequency subbands and the absolute value of the difference of the low-frequency subbands are conducted,the weight is calculated by the average gradient,and finally the fused low-frequency subbands are obtained.At the same time,the high-frequency subbands are fused by adaptive PCNN fusion rule,the motivation for PCNN is calculated by sum-modified Laplacian,the linking strength for PCNN is adaptively calculated by the regional spatial frequency of each source images,and the fused high-frequency subbands are obtained according to the ignition map of PCNN.Finally,the fusion image is acquired by the Shearlet inverse transform.One group of artificial simulated multi-focus images named Cameraman and three groups of real multi-focus images named Pepsi,Clock and Peppers are selected respectively for experiments, seven different fusion methods are chosen as a comparison,and four common quality evaluation indexes are used to evaluate the fusion images objectively.The experimental results show that the proposed method has good performance both on subjective vision and objective evaluation.

关 键 词：多聚焦图像融合 SHEARLET变换 脉冲耦合神经网络 平均梯度 空间频率 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]