We propose a method for creating a matte -- the per-pixel foreground color and alpha -- of a person by taking photos or videos in an everyday setting with a handheld camera. Most existing matting methods require a green screen background or a manually created trimap to produce a good matte. Automatic, trimap-free methods are appearing, but are not of comparable quality. In our trimap free approach, we ask the user to take an additional photo of the background without the subject at the time of capture. This step requires a small amount of foresight but is far less time-consuming than creating a trimap. We train a deep network with an adversarial loss to predict the matte. We first train a matting network with supervised loss on ground truth data with synthetic composites. To bridge the domain gap to real imagery with no labeling, we train another matting network guided by the first network and by a discriminator that judges the quality of composites. We demonstrate results on a wide variety of photos and videos and show significant improvement over the state of the art.

该论文提出了一种使用手持相机在日常环境中通过拍摄照片或视频来创建人物的alpha通道。论文使用基于深度学习的对抗性损失训练了两个抠图网络，能够有效地自动抠图，而无需使用绿幕或手动抠图，相比已有的抠图方法取得了显著的改进。

背景抠像：让世界成为你的绿幕