Range estimation from intensity gradient analysis

The authors have developed a depth-recovery technique that completely avoids the computationally intensive steps of feature selection and correspondence required by conventional approaches. The intensity gradient analysis (IGA) technique is a depth-recovery algorithm that utilizes the properties of the MCSO (moving camera, stationary objects) scenario. Depth values are obtained by analyzing temporal intensity gradients arising from the optic flow field induced by known camera motion. In doing so, IGA avoids the feature extraction and correspondence steps of conventional approaches and is therefore very fast. A detailed description of the algorithm is provided along with experimental results from complex laboratory scenes. It is suggested that the most appealing property of this approach is that IGA places little burden on computational resources, and therefore seems ideally suited for real-world robotic applications