DSR: Direct Self-rectification for Uncalibrated Dual-lens Cameras

TL;DR

This paper introduces DSR, a cost-effective and robust self-rectification method for uncalibrated dual-lens cameras that improves stereo matching speed and accuracy without requiring individual calibration.

Contribution

The proposed DSR method enables direct stereo rectification without prior calibration and is robust to slight camera movements, reducing setup complexity and improving performance.

Findings

Outperforms existing self-rectification methods in accuracy

Reduces need for individual offline calibration

Maintains low geometric distortion in rectified images

Abstract

With the developments of dual-lens camera modules,depth information representing the third dimension of thecaptured scenes becomes available for smartphones. It isestimated by stereo matching algorithms, taking as input thetwo views captured by dual-lens cameras at slightly differ-ent viewpoints. Depth-of-field rendering (also be referred toas synthetic defocus or bokeh) is one of the trending depth-based applications. However, to achieve fast depth estima-tion on smartphones, the stereo pairs need to be rectified inthe first place. In this paper, we propose a cost-effective so-lution to perform stereo rectification for dual-lens camerascalled direct self-rectification, short for DSR1. It removesthe need of individual offline calibration for every pair ofdual-lens cameras. In addition, the proposed solution isrobust to the slight movements, e.g., due to collisions, ofthe dual-lens cameras after fabrication. Different with ex-isting self-rectification approaches, our approach computesthe homography in a novel way with zero geometric distor-tions introduced to the master image. It is achieved by di-rectly minimizing the vertical displacements of correspond-ing points between the original master image and the trans-formed slave image. Our method is evaluated on both real-istic and synthetic stereo image pairs, and produces supe-rior results compared to the calibrated rectification or otherself-rectification approaches