Noise reduction apparatus for reducing noise in an input video signal

Abstract

A noise reduction apparatus for reducing the noise in an input video signal. The input video signal contains pixel data; and, the noise reduction apparatus has a first delay, a subtractor, a second delay, a transformer, a nonlinear calculator, an inverse-transformer, and an adder. The first delay delays an input video signal to derive a first delayed video signal. The subtractor subtracts the first delayed video signal from the input video signal, and outputs a finite difference signal. The second delay delays the finite difference signal by one horizontal scanning period. The transformer forms a signal block from the field difference signal which includes a first predetermined number of pixel data; and, in the signal block, transforms the pixel data into a second predetermined number of characteristic components based on the finite difference signal and the finite difference signal delayed by the second delay. The transformer shifts the signal block one pixel in a predetermined direction after every transforming operation. The nonlinear calculator applies a nonlinear calculation to the characteristic components. The inverse-transformer derives one compensation output corresponding to the signal block on the basis of the output signal of said nonlinear calculator. The adder adds the compensation output to the input video signal to reduce the noise in the input video signal.

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