Patent US 4,202,011

A television signal coder of the type which makes use of correlations to compress the amount of information transmitted. n fields are selected for every m fields (m, n being positive integers; m>n), and a predicted signal level for each picture element in the n fields is represented by an interpolated value of the respective spatially corresponding picture elements in the preceding and succeeding fields. The prediction error which is the difference between the interpolated value and each corresponding picture element is coded and transmitted. The signal for the remaining (m-n) fields are coded and transmitted according to conventional coding systems.