CAJ | 학술논문

根据图像二维结构张量的特性和清晰图像及其模糊副本之间存在较大差异的特点，构造单幅图像的三维结构张量，其特征值大小反映了图像的局部几何结构信息，并与图像的清晰度有关，据此提出基于三维结构张量的图像模糊度评价方法。对输入图像进行不同尺度的低通滤波，得到输入图像的2个副本，并将其分成互不重叠的块。通过计算各块的三维结构张量得到模糊度参数，将各块的模糊度参数和关注度系数加权得到整幅图像的模糊度参数，以模糊度参数的指数函数形式计算图像的模糊度。实验结果表明，该方法计算出的模糊度相对于图像的模糊程度是单调的，具有良好的抗噪性，并且符合人眼视觉系统特性。
근거도상이유결구장량적특성화청석도상급기모호부본지간존재교대차이적특점，구조단폭도상적삼유결구장량，기특정치대소반영료도상적국부궤하결구신식，병여도상적청석도유관，거차제출기우삼유결구장량적도상모호도평개방법。대수입도상진행불동척도적저통려파，득도수입도상적2개부본，병장기분성호불중첩적괴。통과계산각괴적삼유결구장량득도모호도삼수，장각괴적모호도삼수화관주도계수가권득도정폭도상적모호도삼수，이모호도삼수적지수함수형식계산도상적모호도。실험결과표명，해방법계산출적모호도상대우도상적모호정도시단조적，구유량호적항조성，병차부합인안시각계통특성。
Theoretical and experimental studies have shown that the 2D tensor of an image can characterize the local structure and there is a high difference between a sharp image and its blurred version. Based on these studies, a novel 3D structure tensor representation of a single image is proposed, whose eigenvalues can characterize the local geometry structure and have a close relationship with image quality, and then a new blur degree assessment method is proposed. The flow chart of the proposed method blurs the input image with a weak and strong low-pass filters firstly, and divides the input image into no overlapped patches, then computes eigenvalues of the 3D structure tensor and blur measuring parameter of each block, finally computes the blur degree of an image by the exponential function of the blur measuring parameters and visual attention weights of each patch. Experimental results show that the proposed method is monotonic, robust to additive noises, and also consistent with human visual system.