OSL has the texture command that we can use to load image files and map in an object. Dfelinto made a nice video about it some years ago. https://www.youtube.com/watch?v=V5N2rnFtSlw
We also have many samples of it in the source of blender: https://github.com/dfelinto/blender/blob/master/intern/cycles/kernel/shaders/node_image_texture.osl
But how we can load using OSL an blender's internal image? Some created inside it or already loaded using the uv/image editor?