中文摘要：

针对眼底图像配准后直接叠加产生的接缝及如何保证多幅图像融合后细节信息不丢失的问题,提出层次式优化的多频带眼底图像融合方法.该方法通过多阈值分割获取掩模图像并计算其欧式距离得到各层次图像蒙版;根据欧氏距离值及拉普拉斯能量和设计每层蒙版图像的改进加权系数.构建基于信息熵、空间频率和清晰度的图像融合联合客观评价方法进行分析.最后,利用配准误差及重叠率对图像序列进行分组融合后进入下一层,对于奇数幅图像序列中没有组合的图像直接放入下一层.再根据分组规则重新分组进行优化融合,实现层次式的多幅眼底图像优化融合.通过对75组取自福建省附属第一医院眼科及眼底相机实验系统的图像序列,涉及4 898组图像对（正常眼底图像2 952对,病变眼底图像1 946对）进行测试与验证,结果表明,提出方法在有效除去拼接缝的同时,融合图像在重叠区域的RMSE值约为（0.1士0.05）像素.提出的融合方法在客观评价和主观视觉效果之间取得了较好的平衡.

英文摘要：

In order to remove the seams and ensure information details are not missed in the image fusion,the multi-band blending image fusion method for multi-fundus image was proposed in this paper based on hierarchical optimization fusion.The mask image is achieved by multi-threshold segmentation and Euclidean distance transform.And the improved weighted coefficients are designed based on the distance value in the overlap region and the layers of Gaussian image sum of Laplacian energy for the mask image.The combined objective evaluation was proposed that it is based on information entropy,spatial frequency and definition.The registration error and overlap rate are used to realize hierarchical optimization multi-band image fusion method for grouping fusion.And the image alone is put into next level directly.75 group image sequences are applied involving 4 898 set of images （normal fundus image 2 952 pairs and disease fundus image 1 946 pairs） for testing and validation.The results show that the proposed method is effective that removes the seam and obtains the RMSE value of about （0.1 ± 0.05） pixels in overlap region.The proposed method can make equilibrium between objective evaluation and subjective visual effect.