Authors
Leonardo Souto Ferreira 1,2, Leonardo Koller Sacht 1
- UFSC - Universidade Federal de Santa Catarina - Campus Universitório Trindade, Florianópolis 8804-900, Brazil
- UNESP - Universidade Estadual Paulista Júlio de Mesquita Filho, IFT - Instituto de Física Teórica, Rua Dr. Bento Teobaldo Ferraz, 271 - Bloco II - Várzea da Barra Funda, São Paulo 01140-070, Brazil
https://doi.org/10.1016/j.cag.2020.09.011
Highlights
- Spherical imaging benefits from linear blend skinning with Möbius transformations.
- Our method corrects conflicting distortions in 360 degree images.
- All user specified lines in the scene appear straight in the result.
- Objects appear with low conformal distortion in the final image.
- The user can edit the result through different effects in an intuitive interface.
Abstract
We propose a new method to correct distortions in equirectangular images, i.e., images that use the longitude/latitude representation to describe the full spherical field of view around a given viewpoint. We show that Möbius transformations are the correct mathematical tool to deal with the conflicting distortions in this setting: they are conformal, are able to rectify lines, perform rotations, translations and scales on the sphere and are bijective. Multiple transformations are specified through points, lines and cages on the sphere. We associate three points that uniquely define a Möbius transformation to each one of these geometric handles. Linear blend skinning with bounded biharmonic weights combine the different transformations into a single full spherical modified image. We present a collection of results in challenging settings and show that our method is more flexible and produces higher quality results when compared to previous methods.
Files
Code
Stable version Here. For most recent version, please check our github.
Article
https://doi.org/10.1016/j.cag.2020.09.011
Supplementary material
PDF Here. Video coming soon.
Pre-print
Video presentation
Full version
Short version