The Structural Similarity (SSIM) Index is a very widely used image/video quality model that continues to play an important role in the perceptual evaluation of compression algorithms, encoding recipes and numerous other image/video processing algorithms. Several public implementations of the SSIM and Multiscale-SSIM (MS-SSIM) algorithms have been developed, which differ in efficiency and performance. This "bendable ruler" makes the process of quality assessment of encoding algorithms unreliable. To address this situation, we studied and compared the functions and performances of popular and widely used implementations of SSIM, and we also considered a variety of design choices. Based on our studies and experiments, we have arrived at a collection of recommendations on how to use SSIM most effectively, including ways to reduce its computational burden.

中文翻译：

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结构相似性旅行者指南

结构相似性（SSIM）索引是一种非常广泛使用的图像/视频质量模型，在压缩算法，编码配方和许多其他图像/视频处理算法的感知评估中继续发挥重要作用。已经开发了SSIM和Multiscale-SSIM（MS-SSIM）算法的几种公共实现方式，它们在效率和性能上有所不同。这种“可弯曲的标尺”使编码算法的质量评估过程变得不可靠。为了解决这种情况，我们研究并比较了流行的和广泛使用的SSIM实现的功能和性能，并且还考虑了多种设计选择。根据我们的研究和实验，我们就如何最有效地使用SSIM提出了一系列建议，