VSNR: A wavelet-based visual signal-to-noise ratio for natural images
VSNR: A wavelet-based visual signal-to-noise ratio for natural images
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DOI：
10.1109/tip.2007.901820
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发表时间：
2007-09-01
影响因子：
10.6
通讯作者：
Hemami, Sheila S.
中科院分区：
文献类型：
--
作者：
Chandler, Damon M.;Hemami, Sheila S.
基于人类视觉的近阈值和超阈值特性，提出了一种量化自然图像视觉保真度的有效度量方法。提出的度量，视觉信噪比（VSNR），通过两个阶段的方法来操作。在第一阶段，通过基于小波的视觉掩蔽和视觉求和模型计算用于检测自然图像中存在的失真的对比度阈值，以确定失真图像中的失真是否可见。如果畸变低于检测阈值，则认为畸变图像具有完美的视觉保真度（VSNR =无穷大），无需进一步分析。如果失真超过阈值，则应用第二阶段，该阶段基于感知对比度的低级视觉属性和全局优先级的中级视觉属性。这两个特性被建模为多尺度小波分解的形变对比空间中的欧氏距离，并基于这些距离的简单线性和计算VSNR。提出的VSNR度量通常与当前的视觉保真度度量相竞争；它在低计算复杂度和低内存需求方面都是高效的；它基于物理亮度和视角（而不是数字像素值和基于像素的尺寸）来适应不同的观看条件。
This paper presents an efficient metric for quantifying the visual fidelity of natural images based on near-threshold and suprathreshold properties of human vision. The proposed metric, the visual signal-to-noise ratio (VSNR), operates via a two-stage approach. In the first stage, contrast thresholds for detection of distortions in the presence of natural images are computed via wavelet-based models of visual masking and visual summation in order to determine whether the distortions in the distorted image are visible. If the distortions are below the threshold of detection, the distorted image is deemed to be of perfect visual fidelity (VSNR = infinity) and no further analysis is required. If the distortions are suprathreshold, a second stage is applied which operates based on the low-level visual property of perceived contrast, and the mid-level visual property of global precedence. These two properties are modeled as Euclidean distances in distortion-contrast space of a multiscale wavelet decomposition, and VSNR is computed based on a simple linear sum of these distances. The proposed VSNR metric is generally competitive with current metrics of visual fidelity; it is efficient both in terms of its low computational complexity and in terms of its low memory requirements; and it operates based on physical luminances and visual angle (rather than on digital pixel values and pixel-based dimensions) to accommodate different viewing conditions.