1. A method comprising: providing a point of sale system for processing a retail transaction for a plurality of retail products; providing a non-optical three-dimensional imaging system coupled to the point of sale system, the imaging system comprising at least one of a magnetic resonance imager (MRI) system, a computed tomography (CT) scanning system, and a terahertz imaging system; scanning, by the non-optical three-dimensional imaging system a volume occupied by the plurality of retail products to obtain a three dimensional voxel image of the volume; processing, by a computer system, the three dimensional voxel image to identify three-dimensional voxel regions, each three-dimensional voxel region corresponding to a product of the plurality of retail products; identifying, by the computer system, for each three-dimensional voxel region, a symbol on a surface of the each three-dimensional voxel region; identifying, by the computer system, for each three-dimensional voxel region, a product identifier corresponding to the symbol on the surface of the each three-dimensional voxel region; adding, by the point of sale system, the product identifiers for each three dimensional voxel region to the retail transaction; and processing, by the point of sale system, payment for the retail transaction.