Color subspace exploring for natural image matting

Abstract

Abstract Deep neural networks have seen a surge of successful methods in natural image matting. However, the overlap of foreground and background color distributions in an image is still troubling in matting. It is observed that the three color channels contain different contrast information of an image: some color channels may provide clearer contrast information for separating the foreground from the image, while the foreground and background color distributions in other channels may heavily overlap, resulting in blurred foreground‐background boundaries. Motivated by this observation, the Color Subspace Exploring Network (CSEMat) is proposed to extract the foreground object from an image by exploring high‐contrast appearance information in individual color spaces. Specifically, a 4‐branch encoder is constructed, with one branch for the RGB image and three branches for subdividing the color space. Each color channel is individually processed by a sub‐encoder. Additionally, the trimap‐based color information aggregation module (CIA) is introduced to integrate the feature maps from the independent sub‐encoders, facilitating the transfer of optimized features to the decoder. Extensive experiments demonstrate that the proposed CSEMat achieves favorable performance on publicly available matting datasets.

Keywords

• computer vision
• convolution
• convolutional neural nets
• image segmentation