中文摘要：

在不损失彩色图像颜色信息的基础上,通过定义一种全四元数模型将四元数的3个虚部以及实部全部用于表示彩色图像的结构信息,从而在完整保留颜色信息的基础上提高了四元数矩阵的信息承载量。为了进一步增加与主观感知的一致性,将彩色图像的细节信息和颜色分量合并作为四元数的实部和虚部,进而改进传统的图像质量评价结构相似度（SSIM）方法,采用四元数结构相似度方法实现了对待测图像的质量评价。实验结果表明,本文方法既保留了彩色图像的颜色信息,又增强了图像内容中人眼敏感的细节信息,采用LIVE数据库和IVC数据库验证了本文方法的评价指标,实验结果表明,所提指标与人眼主观感知的一致程度要好于传统的图像质量评价方法以及纯四元数SSIM方法。在交叉失真实验中,量化评价结果的Kendall等级相关系数（KRCC）,Spearman等级相关系数（SRCC）以及均方根误差（RMSE）为0.692 9、0.881 8以及7.506,均好于实验中采用的其它几种方法。

英文摘要：

Color information is ignored in most of the image quality assessment methods.Color information and luminance information are two important parts in color image.Loss of color information will result in the low consistency of the assessment results.Aiming to the problem,full-quaternion is defined in this paper.It is used to describe the structure information of a color image.The real part and imagery parts in full quaternion are used to perform the task.It differs from the traditional pure quaternion-based color image description method where the detail information in an image is enhanced by using the real part of a quaternion.To enhance the detail information in an image,local variance of luminance layer and the three color channels are taken as the real part and imagery parts respectively.On the basis of that,the structure similarity（SSIM）measure is studied and the quaternion-based structure similarity measure is used to perform color image structure comparison.Results from the experiments show that the proposed method combines detail information and color information of a color image.It can describe the structure information better than the traditional description methods.The quantitative results reveal that the performance of the full quaternion-based method is better than the pure quaternion-based method and many state-of-the-art methods.The values of Kendall rank correlation coefficient（KRCC）,spearman rank correlation coefficient（SRCC）and root mean squared error（RMSE）are 0.692 9,0.881 8and 7.506,respectively,which proves that the performance of the proposed method is better than the other methods in the experiment.