Depth360: Self-supervised Learning for Monocular Depth Estimation using Learnable Camera Distortion Model
Self-supervised monocular depth estimation has been widely investigated to
estimate depth images and relative poses from RGB images. This framework is
attractive for researchers because the depth and pose networks can be trained
from just time sequence images without the need for the ground truth depth and
poses.
In this work, we estimate the depth around a robot (360 degree view) using
time sequence spherical camera images, from a camera whose parameters are
unknown. We propose a learnable axisymmetric camera model which accepts
distorted spherical camera images with two fisheye camera images. In addition,
we trained our models with a photo-realistic simulator to generate ground truth
depth images to provide supervision. Moreover, we introduced loss functions to
provide floor constraints to reduce artifacts that can result from reflective
floor surfaces. We demonstrate the efficacy of our method using the spherical
camera images from the GO Stanford dataset and pinhole camera images from the
KITTI dataset to compare our method's performance with that of baseline method
in learning the camera parameters.