METHOD AND APPARATUS FOR ENCODING AND DECODING VIDEO

摘要

The disclosure is directed to an apparatus and method for encoding and/or decoding video signals for use in a compatible high definition television system or in other applications. In a form of the disclosure there is provided an encoder which stores an input frame as an array of digital pixel values. The stored array is interrogated to generate a sum signal and at least one difference signal. The sum signal is representative of the sum of the pixel values in a group of pixels. The difference signal is representative of the difference between the total of the pixel values in some of the pixels in the group and the total of the pixel values of other pixels in the group. The sum signal and the difference signal are generated for a multiplicity of groups which cover the video frame. The sum signal is generated at a relatively high information rate and the difference signal is generated at a relatively low information rate. In the decoder the sum and difference signals are combined to obtain an output pixel value for each pixel of an output video frame.