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补丁复杂性、 有限像素相关性和最优去噪Patch Complexity, Finite Pixel Correlations and Optimal Denoising |
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| 课程网址: | http://videolectures.net/eccv2012_levin_denoising/ |
| 主讲教师: | Laurent Itti; Anat Levin; Ramin Zabih |
| 开课单位: | 魏茨曼科学研究所 |
| 开课时间: | 2012-11-12 |
| 课程语种: | 英语 |
| 中文简介: |  |
| 课程简介: | Image restoration tasks are ill-posed problems, typically solved with priors. Since the optimal prior is the exact unknown density of natural images, actual priors are only approximate and typically restricted to small patches. This raises several questions: How much may we hope to improve current restoration results with future sophisticated algorithms? And more fundamentally, even with perfect knowledge of natural image statistics, what is the inherent ambiguity of the problem? In addition, since most current methods are limited to finite support patches or kernels, what is the relation between the patch complexity of natural images, patch size, and restoration errors? Focusing on image denoising, we make several contributions. First, in light of computational constraints, we study the relation between denoising gain and sample size requirements in a non parametric approach. We present a law of diminishing return, namely that with increasing patch size, rare patches not only require a much larger dataset, but also gain little from it. This result suggests novel adaptive variable-sized patch schemes for denoising. Second, we study absolute denoising limits, regardless of the algorithm used, and the converge rate to them as a function of patch size. Scale invariance of natural images plays a key role here and implies both a strictly positive lower bound on denoising and a power law convergence. Extrapolating this parametric law gives a ballpark estimate of the best achievable denoising, suggesting that some improvement, although modest, is still possible. |
| 关 键 词: | 计算机视觉; 图像修复; 图像去燥 |
| 课程来源: | 视频讲座网 |
| 最后编审: | 2021-03-12：nkq |
| 阅读次数: | 45 |