中文摘要：

提出一种针对循环群和二面体群对称性图像的“旋转不变”去噪算法。该算法利用对称性图像的旋转不变（对于二面体群对称性同时包含对称轴反射不变）特性，通过旋转（或附加对称轴反射）、累加达到图像去噪的目的。数值实验表明，与其它去噪算法相比，“旋转不变”算法能很好去除噪声，恢复原图像。

英文摘要：

A rotation-invariant denoising algorithm is proposed for restoring noisy images with cyclicr and dihedral symmetries. Based on the rotation-invariant （or plus reflection invariant） characteristic of cyclic （or dihedral） images, the proposed algorithm is performed successfully by rotating （or plus reflecting） and summing the noisy images. Experimental results show that, compared with other classic denoising methods, the proposed algorithm can restore the symmetric images efficiently.