Apparatus and method for reducing quantization error in digital image signals

摘要

A system for processing digital image signals to reduce the effect of quantizing noise in the images represented by the signals. An n-bit image signal is converted into an m-bit image signal (m>n). The high frequency content of the m-bit signal is estimated and then first and second multipliers are derived on the basis of the high frequency content. The first multiplier is applied to the m-bit image signal, the second multiplier is applied to a filtered version of the m-bit image signal, and the two resulting signals are combined to generate a reduced quantizing noise m-bit image signal.