Unsupervised monocular depth estimation with aggregating image features and wavelet SSIM (Structural SIMilarity) loss

Abstract

Unsupervised learning has shown to be effective for image depth prediction.However, the accuracy is restricted because of uncertain moving objects and the lack of other proper constraints.This paper focuses on how to improve the accuracy of depth prediction without increasing the computational burden of the depth network.Aggregated residual transformations are embedded in the depth network to extract high-dimensional image features.A more accurate mapping relationship between feature map and depth map can be built without bringing extra network computational burden.Additionally, the 2D discrete wavelet transform is applied to the structural similarity loss (SSIM) to reduce the photometric loss effectively, which can divide the entire image into various patches and obtain high-quality image information.Finally, the effectiveness of the proposed method is demonstrated.The training model can improve the performance of the depth network on the KITTI dataset and decrease the domain gap on the Make3D dataset.