An Efficient Multi-Estimation-Based Parameter Centroid Decision via Linear Regression Approach

We propose a novel post-processing approach for the local optimization of Locally Optimized RANdom SAmple Consensus (LO-RANSAC), called the Multi-Estimation-based Parameter Centroid (MEPC) decision. It is observed that the optimal thresholds for hypothesis generation and evaluation differ in local optimization with the inner RANSAC. Instead of binary labeling for inliers and outliers, a new ternary labeling for inliers, midliers, and outliers is introduced, using two thresholds. Our experimental results show that the highest-scoring model measured by the ternary method is closer to the real model than that measured by the existing binary method. However, it should be noted that the highest score still does not correspond to the best model due to inaccurate evaluation by data noise. We introduce a new linear model centroid decision method to compensate for the highest-scoring model distorted by noise. In this process, an efficient method for measuring the similarity between two hypotheses is introduced, and candidates close to the real model are found by comparing their similarity with the highest-scoring model. Our approach determines a representative model of the multiple candidate hypotheses, which is defined as the geometric centroid of hyperplanes. We test on various datasets for homography, fundamental, and essential matrices, demonstrating that applying MEPC to existing RANSAC algorithms achieves more accurate and stable model estimation. Moreover, additional experiments on vanishing point detection show the potential of our approach for various model estimation applications.