Two-dimensional noise shaping filter circuit

摘要

A two-dimensional noise shaping filter circuit including a first adder for adding a feedback signal to the input signal A quantizer is provided for quantizing an output from the first adder. A second adder adds an output from the quantizer to the output from the first adder. A transfer function unit provides an output from the second adder with a two-dimensional transfer function so as to generate the feedback signal to be supplied to the first adder. Using the noise shaping filter circuit, it becomes possible to provide a video signal with a two-dimensional noise shaping process, not only for a present line but also for a preceding line and a succeeding line. White noises caused by the quantizing process can be moved towards corners of a square Brillouin zone. Noise levels can be decreased at desired locations, such as at a portion of the center of a screen having a lower spatial frequency.