Shared Sampling for Real-Time Alpha Matting
Shared Sampling for Real-Time Alpha Matting
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DOI：
10.1111/j.1467-8659.2009.01627.x
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发表时间：
2010-01-01
影响因子：
2.5
通讯作者：
Oliveira, Manuel M.
中科院分区：
文献类型：
--
作者：
Gastal, Eduardo S. L.;Oliveira, Manuel M.
图像抠图的目的是通过颜色和不透明度（alpha）估计从图像中提取前景元素。虽然近年来在提高抠图技术的准确性方面取得了很大的进展，但一个普遍的问题仍然存在：抠图计算速度慢。我们提出了第一个用于自然图像和视频的实时抠图技术。我们的技术是基于这样的观察：对于小的邻域，像素倾向于共享相似的属性。因此，单独处理三图中未知区域的每个像素会导致大量的冗余工作。我们展示了如何通过对背景和前景样本的仔细选择来显著和安全地减少这种计算。与之前的技术相比，我们的技术实现了高达两个数量级的加速，同时产生了高质量的alpha mattes。我们的结果质量已通过独立基准验证。我们技术的速度第一次实现了视频的实时alpha抠图，并有可能实现一类新的令人兴奋的应用。
Image matting aims at extracting foreground elements from an image by means of color and opacity (alpha) estimation. While a lot of progress has been made in recent years on improving the accuracy of matting techniques, one common problem persisted: the low speed of matte computation. We present the first real-time matting technique for natural images and videos. Our technique is based on the observation that, for small neighborhoods, pixels tend to share similar attributes. Therefore, independently treating each pixel in the unknown regions of a trimap results in a lot of redundant work. We show how this computation can be significantly and safely reduced by means of a careful selection of pairs of background and foreground samples. Our technique achieves speedups of up to two orders of magnitude compared to previous ones, while producing high-quality alpha mattes. The quality of our results has been verified through an independent benchmark. The speed of our technique enables, for the first time, real-time alpha matting of videos, and has the potential to enable a new class of exciting applications.