_:b663965590 . _:b663965590 . _:b663965590 . _:b663965590 "A relationship that holds between two images, A and B, where:\nA depicts X;\nB depicts Y;\nX and Y are both of type T'\nC is a 2 layer image consiting of layers A and B;\nA and B are aligned in C according to a shared co-ordinate framework so that common features of X and Y are co-incident with each other.\nNote: A and B may be 2D or 3D.\nExamples include: the relationship between two channels collected simultaneously from a confocal microscope; the relationship between an image dpeicting X and a painted annotation layer that delineates regions of X; the relationship between the tracing of a neuron on an EM stack and the co-ordinate space of the stack; the relationship between two separately collected images that have been brought into register via some image registration software." . _:b663965590 . _:b663965590 . _:b663965590 .