Omnidirectional images generally have nonlinear distortion in radial direction. Unfortunately. traditional algorithms such as scale-invariant feature transform (SIFT) and Descriptor-Nets (D-Nets) do not work well in matching omnidirectional images just because they are incapable of dealing with the distortion. In order to solve this problem. https://www.kerrenneur.com/product-category/food-service-food-serviceother-restaurant/