US Patent 10289875 Embedding data on objects using surface modulation

Methods and apparatus are disclosed for embedding static information (such as serial numbers, etc.) on objects by modifying their exterior shape slightly, dubbed surface modulation. Data is embedded when the object is created and can then be read using readers with the appropriate resolution. According to one example of the disclosed technology, a method of embedding data expressed as a binary sequence onto an object surface includes establishing a coordinate system over an object surface, computing a transform of the coordinate system to a frequency domain, mapping the binary sequence to an integer value, replacing the highest frequency coefficient of the transform with the integer value, computing an inverse of the transform, producing a vector expressed in the coordinate system, and fabricating at least a portion of the object surface according to the vector.