- Multi-view image stitching
Image stitching techniques align two images captured at different viewing positions onto a single wider image. When the captured 3D scene is not planar and the camera baseline is large, two images exhibit parallax where the relative positions of scene structures are quite different from each view. The existing image stitching methods often fail to work on the images with large parallax. In this paper,we propose a reliable image stitching algorithm robust to large parallax based on the novel concept of warping residuals. We ﬁrst estimate multiple homographies and find their inlier feature matches, respectively, between two images. Then we evaluate warping residual for each feature match with respect to the multiple homographies. To alleviate the parallax artifacts, we partition input images into superpixels and warp each superpixel adaptively according to an optimal homography which is computed by minimizing the error of feature matches weighted by the warping residuals. Experimental results demonstrate that the proposed algorithm provides accurate stitching results for images with large parallax, and outperforms the existing methods qualitatively and quantitatively.
- Multi-view video stitching
Conventional stitching techniques for images and videos are based on planar warping models, and therefore, they often fail to work on multi-view images and videos which exhibit large parallax and include diverse non-planar structures at different scene depths. In this paper, we propose a novel video stitching algorithm for such challenging multi-view videos. We first separate the multiple foreground objects from the background, which are then warped adaptively based on the epipolar geometry. We estimate the parameters of ground plane homography, fundamental matrix, and vertical vanishing points reliably, using both of the appearance and activity based feature matches validated by geometric constraints. While the ground plane pixels are warped by the homography, we warp the off-plane pixels into geometrically accurate matching positions through their ground plane pixels to alleviate the parallax artifacts adaptively. We also exploit the inter-view and inter-frame correspondence matching information together to estimate the ground plane pixels, which are then refined by energy minimization. Experimental results show that the proposed algorithm provides geometrically accurate stitching results of multi-view videos with large parallax and outperforms the state-of-the-art image stitching methods qualitatively and quantitatively.
|||Kyu-Yul Lee and Jae-Young Sim, “Stitching for Multi-View Videos With Large Parallax Based on Adaptive Pixel Warping,” IEEE Access, May. 2018. [more]|