基于梯度结构相似度的无参考模糊图像质量评价

在对模糊图像边缘膨胀后进行边缘膨胀块提取的 基础上,提出一种基于梯 度结构相似度(GSIM)的无参考模糊图像质量评价方法(NRGSIM)。首先,将原始模糊图像经过低 通滤波生成再模糊图像；之后,将原始模糊图像生成的边缘膨胀图像进行8×8分块,并将子块 划分为边缘膨胀块和平滑块；然后,计算原始模糊图像和再模糊图像中所有对应到边缘膨胀 图 中边缘膨胀块的相应子块的GSIM；最后,平均得到整幅图像的模糊值。在4个数据 库上实验结果表明,本文方法评价结果合理、稳定,更加符合人类视觉特性,与主观评分有 较好的一致性,而且计算简单,取得了很好的评价效果,LIVE2数据库上的SROCC指标达到0.964。

No-reference blur image quality assemssment based on gradient similarity

With the popularity of the consumer el ectronic products,such as cell phone and other low-cost digital cameras,a large number of digital images are generated to promote interest in the study of the no-reference objective image quality assessment algorithm.In this paper,based o n the extracted edge dilation block from blur edge dilation image,a novel no-re ference image quality assessment scheme using gradient structural similarity (NR GSIM) is proposed for quality evaluation of blurred images.In this method,firstl y the re-blurred image is produced by blurring the original blurred image with a low pass filter.Then the edge dilation image is divided into 8×8blocks.The s ub-blocks are classified into edge dilation block and smooth block.The gradient structural similarity index is given by different weighs according to different types of blocks.Finally,the blur estimation of the whole image is produced.Expe rimental results on four open blur image databases show that the proposed metric is more reasonable and stable than other methods.It obtains high consistence wi th subjective quality evaluations and has easy calculation.It is more consistent with human visual system.So the proposed metric is appropriate for no-referenc e blurred image quality assessment.The index of SROCC on LIVE2database is 0.9641.