Replacing Computed tomography (CT) with magnetic resonance image (MRI), MRI- positron electron tomography (PET) or MRI- single photon emission computed tomography (SPECT) imaging might have further advantages due to higher soft-tissue contrast of brain structure and lower dose absorbed by the patient. In this paper, a new three-layer (intensity, detail, and base layers) medical image fusion method with differential features for gray and pseudo-color images is proposed. The proposed method includes three steps. At the first step, differential feature by structure tensor is used to decompose the anatomical MRI medical image into its three-layer image representation. On the other side, differential feature by color tensor is adopted to decompose the functional PET or SPECT medical image into its three-layer image representation. At the second step, spatial frequency metric is proposed to combine the decomposed intensity layers and detail layers and absolute maximum is defined as the image fusion rule of the base layers. At the third step, the fused image is obtained by the addition of the fused intensity layer, the fused detail layer, and the fused base layer. The superiority of the proposed method is demonstrated by subjective and objective evaluation on experimental results.

用磁共振成像（MRI），MRI-正电子电子断层扫描（PET）或MRI-单光子发射计算机断层扫描（SPECT）成像代替计算机断层扫描（CT）可能会具有更多的优势，因为大脑结构的软组织对比度较高，而脑部结构较低病人吸收的剂量。本文提出了一种新的具有差异特征的三层（强度，细节和基础层）医学图像融合方法，用于灰度和伪彩色图像。所提出的方法包括三个步骤。第一步，使用按结构张量的差分特征将解剖MRI医学图像分解为其三层图像表示。另一方面，采用基于颜色张量的差分特征将功能性PET或SPECT医学图像分解为三层图像表示。在第二步 提出了空间频率度量，将分解后的强度层和细节层结合起来，并将绝对最大值定义为基础层的图像融合规则。在第三步骤，通过添加融合强度层，融合细节层和融合基础层来获得融合图像。通过对实验结果进行主观和客观评估，证明了该方法的优越性。