SSIM介绍 结构相似性指数(structural similarity index,SSIM), 出自参考文献[1],用于度量两幅图像间的结构相似性。和被广泛采用的L2 loss不同,SSIM和人类的视觉系统(HVS)类似,对局部结构变化的感知敏感。 SSIM分为三个部分:照明度、对比度、结构,分别如下公式所示: 将上面三个式子汇总到一起就是SSIM: 其中,上式...
结构相似性指标(structural similarity index,SSIM index)是一种用以衡量两张数位影像相似程度的指标。当两张影像其中一张为无失真影像,另一张为失真后的影像,二者的结构相似性可以看成是失真影像的影像品质衡量指标。相较于传统所使用的影像品质衡量指标,像是峰值信噪比(PSNR),结构相似性在影像品质的衡量上更能符合...
在这里,经过一些实验总结,我们把K1设为0.01,K2设为0.03,然后用平均SSIM指数作为整幅图像的估计质量评价: (14) 其中X,Y为图像, 为局部SSIM指数在映射中的位置,MN为局部窗口的数量。 四、matlab实现 function [mssim, ssim_map,siga_sq,sigb_sq] = SSIM(ima, imb) % === %ssim的算法主要参考如下论文: %...
Introduction— The Structural Similarity Index (SSIM) is a perceptual metric that quantifies image quality degradation* caused by processing such as data compression or by losses in data transmission. It is a full reference metric that requires two images from the same image capture— a reference...
Introduction—TheStructural Similarity Index (SSIM)is a perceptual metric that quantifies image quality degradation* caused by processing such as data compression or by losses in data transmission. It is a full reference metric that requirestwoimages from the same image capture— a reference image ...
SSIMPurpose: To apply an imaging metric of the Structural SIMilarity (SSIM) index to the radiotherapy dose verification field and evaluate its capability to reveal the different types of errors between two dose distributions. Method: The SSIM index consists of three sub-indices: luminance, contrast...
___= ssim(A,ref,Name,Value)computes the SSIM, using name-value pairs to control aspects of the computation. Examples collapse all Calculate Structural Similarity Index (SSIM) View MATLAB Command Read an image into the workspace. Create another version of the image, applying a blurring filter....
This MATLAB function calculates the structural similarity (SSIM) index for grayscale image or volume A using ref as the reference image or volume.
[ssimval,ssimmap] = ssim(___)also returns the local SSIM value for each pixel or voxel inA. collapse all Calculate Structural Similarity Index (SSIM) Read an image into the workspace. Create another version of the image, applying a blurring filter. ...
data[0] print("Initial ssim:", ssim_value) # Module: pytorch_ssim.SSIM(window_size = 11, size_average = True) ssim_loss = pytorch_ssim.SSIM() optimizer = optim.Adam([img2], lr=0.01) while ssim_value < 0.95: optimizer.zero_grad() ssim_out = -ssim_loss(img1, img2) ssim_...