Objective Quality Assessment for Color-to-Gray Image Conversion
Objective Quality Assessment for Color-to-Gray Image Conversion
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DOI：
10.1109/tip.2015.2460015
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发表时间：
2015-12-01
影响因子：
10.6
通讯作者：
Wang, Zhou
中科院分区：
文献类型：
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作者：
Ma, Kede;Zhao, Tiesong;Wang, Zhou
彩色到灰度(C2G)图像转换是将彩色图像转换为灰度图像的过程。尽管它在现实世界的应用中得到了广泛的应用，但很少有人致力于比较C2G转换算法的性能。主观评价是可靠的，但也不方便、耗时。在这里，我们首次尝试开发一个客观质量模型，该模型自动预测C2G转换图像的感知质量。受结构相似性指数思想的启发，我们提出了一种C2G结构相似性指数(C2G-SSIM)，用于评价参考彩色图像和C2G转换图像之间的亮度、对比度和结构相似性。然后，根据图像类型将这三个组件组合在一起，以产生总体质量度量。实验结果表明，提出的C2G-SSIM指标与主观评价结果吻合较好，显著优于现有的C2G转换客观质量指标。为了挖掘C2G-SSIM的潜力，我们进一步展示了它在两个方面的应用：1)C2G转换算法的自动参数调整；2)C2G转换图像的自适应融合。
Color-to-gray (C2G) image conversion is the process of transforming a color image into a grayscale one. Despite its wide usage in real-world applications, little work has been dedicated to compare the performance of C2G conversion algorithms. Subjective evaluation is reliable but is also inconvenient and time consuming. Here, we make one of the first attempts to develop an objective quality model that automatically predicts the perceived quality of C2G converted images. Inspired by the philosophy of the structural similarity index, we propose a C2G structural similarity (C2G-SSIM) index, which evaluates the luminance, contrast, and structure similarities between the reference color image and the C2G converted image. The three components are then combined depending on image type to yield an overall quality measure. Experimental results show that the proposed C2G-SSIM index has close agreement with subjective rankings and significantly outperforms existing objective quality metrics for C2G conversion. To explore the potentials of C2G-SSIM, we further demonstrate its use in two applications: 1) automatic parameter tuning for C2G conversion algorithms and 2) adaptive fusion of C2G converted images.