Most existing multi-focus color image fusion methods based on multi-scale decomposition consider three color components separately during fusion, which leads to inherent color structures change, and causes tonal distortion and blur in the fusion results. In order to address these problems, a novel fusion algorithm based on the quaternion multi-scale singular value decomposition (QMSVD) is proposed in this paper. First, the multi-focus color images, which represented by quaternion, to be fused is decomposed by multichannel QMSVD, and the low-frequency sub-image represented by one channel and high-frequency sub-image represented by multiple channels are obtained. Second, the activity level and matching level are exploited in the focus decision mapping of the low-frequency sub-image fusion, with the former calculated by using local window energy and the latter measured by the color difference between color pixels expressed by a quaternion. Third, the fusion results of low-frequency coefficients are incorporated into the fusion of high-frequency sub-images, and a local contrast fusion rule based on the integration of high-frequency and low-frequency regions is proposed. Finally, the fused images are reconstructed employing inverse transform of the QMSVD. Simulation results show that image fusion using this method achieves great overall visual effects, with high resolution images, rich colors, and low information loss.

中文翻译：

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基于四元数多尺度奇异值分解的多焦点彩色图像融合

现有大多数基于多尺度分解的多焦点彩色图像融合方法在融合过程中分别考虑三个颜色分量，这导致固有的颜色结构变化，并导致融合结果中的色调失真和模糊。为了解决这些问题，提出了一种基于四元数多尺度奇异值分解（QMSVD）的融合算法。首先，通过多通道QMSVD分解由四元数表示的要融合的多焦点彩色图像，并且获得由一个通道表示的低频子图像和由多个通道表示的高频子图像。其次，在低频子图像融合的焦点决策映射中利用活动水平和匹配水平，前者通过使用局部窗口能量来计算，而后者则通过四元数表示的彩色像素之间的色差来测量。第三，将低频系数的融合结果结合到高频子图像的融合中，提出了基于高频和低频区域融合的局部对比度融合规则。最后，采用QMSVD的逆变换重建融合图像。仿真结果表明，采用该方法的图像融合具有较高的整体视觉效果，图像分辨率高，色彩丰富，信息丢失少。提出了一种基于高频和低频区域融合的局部对比度融合规则。最后，采用QMSVD的逆变换重建融合图像。仿真结果表明，采用该方法的图像融合具有较高的整体视觉效果，图像分辨率高，色彩丰富，信息丢失少。提出了一种基于高频和低频区域融合的局部对比度融合规则。最后，采用QMSVD的逆变换重建融合图像。仿真结果表明，采用该方法的图像融合具有较高的整体视觉效果，图像分辨率高，色彩丰富，信息丢失少。