# A Fast Free-viewpoint Video Synthesis Algorithm for Sports Scenes

## TL;DR

This paper introduces a parallel algorithm for fast free-viewpoint video synthesis of sports scenes, combining efficient 3D reconstruction and view-dependent rendering to improve speed and visual quality.

## Contribution

It presents a novel parallel approach that accelerates 3D scene reconstruction and rendering for sports videos using visual hulls and ROI-based processing.

## Key findings

- Significant reduction in processing time for sports scene reconstruction.
- High-quality visual results demonstrated on volleyball and judo sequences.
- Effective handling of occlusions with view-dependent rendering.

## Abstract

In this paper, we report on a parallel freeviewpoint video synthesis algorithm that can efficiently reconstruct a high-quality 3D scene representation of sports scenes. The proposed method focuses on a scene that is captured by multiple synchronized cameras featuring wide-baselines. The following strategies are introduced to accelerate the production of a free-viewpoint video taking the improvement of visual quality into account: (1) a sparse point cloud is reconstructed using a volumetric visual hull approach, and an exact 3D ROI is found for each object using an efficient connected components labeling algorithm. Next, the reconstruction of a dense point cloud is accelerated by implementing visual hull only in the ROIs; (2) an accurate polyhedral surface mesh is built by estimating the exact intersections between grid cells and the visual hull; (3) the appearance of the reconstructed presentation is reproduced in a view-dependent manner that respectively renders the non-occluded and occluded region with the nearest camera and its neighboring cameras. The production for volleyball and judo sequences demonstrates the effectiveness of our method in terms of both execution time and visual quality.