Compatible high-definition television system utilizing Hadamard basis functions

摘要

A compatible high-definition television system may be achieved by dividing a standard picture element into four arranged sub-picture elements arranged in a parallelo-grammatic fashion. In the system a sum signal which is the sum of the four sub-picture elements is transmitted as a standard luminance signal. Further, the system includes means for computing three difference signals and transmitting these in separate channels. The first difference signal is the horizontal difference signal, the second is a vertical difference signal and the third is the diagonal difference signal. These four signals are an orthogonal set of 2×2 Hadamard basis functions. To reconstruct the high-definition television sub-picture element values, the three difference signals and the sum signal are summed to determine the orthogonal sub-pixel values. The system uses simple hardware and does not require a frame buffer.