CMLA, École Normale Supérieure de Cachan, Cachan, France.
IEEE Trans Image Process. 2011 Nov;20(11):3073-85. doi: 10.1109/TIP.2011.2142318. Epub 2011 Apr 15.
This work is concerned with the modification of the gray level or color distribution of digital images. A common drawback of classical methods aiming at such modifications is the revealing of artefacts or the attenuation of details and textures. In this work, we propose a generic filtering method enabling, given the original image and the radiometrically corrected one, to suppress artefacts while preserving details. The approach relies on the key observation that artefacts correspond to spatial irregularity of the so-called transportation map, defined as the difference between the original and the corrected image. The proposed method draws on the nonlocal Yaroslavsky filter to regularize the transportation map. The efficiency of the method is shown on various radiometric modifications: contrast equalization, midway histogram, color enhancement, and color transfer. A comparison with related approaches is also provided.
这项工作涉及数字图像的灰度级或颜色分布的修改。旨在进行此类修改的经典方法的一个常见缺点是会揭示伪影或降低细节和纹理的质量。在这项工作中，我们提出了一种通用的滤波方法，该方法可以在给定原始图像和辐射校正图像的情况下，在保留细节的同时抑制伪影。该方法基于一个关键的观察结果，即伪影对应于所谓的运输图的空间不规则性，运输图定义为原始图像和校正图像之间的差异。所提出的方法利用非局部 Yaroslavsky 滤波器来正则化运输图。该方法在各种辐射修正方面的效率得到了展示：对比度均衡、中间直方图、颜色增强和颜色传递。还提供了与相关方法的比较。
