Texture mapping in compositing is yet another time-saving technique that facilitates in wrapping a texture to a mesh. The UV pass, as a 32-bit float image, is required to perform this wrapping.
The Map UV node in Blender should be used to perform texture mapping at the compositing stage.
As illustrated in the following screenshot, a Texture and UV Pass have to be connected to the respective sockets of the Map UV node to attain the wrapping. As seen in the following example, the sphere and plane rendered without any textures are wrapped with a texture using a map UV node.
This technique allows the user to be able to modify specific object textures in compositing without needing a 3D rerendering. This can save a huge amount of time in the CG film production process, where creative changes are bound to happen at any stage.