Noise reduction device and noise reduction method

Abstract

The invention discloses a noise reduction device and a noise reduction method. The noise reduction device comprises a DC removal unit for removing a DC component of a luminance; a first wavelet transform unit for performing a wavelet transform on an output of the DC removal unit for outputting a first low and high band signals; a first low and high band noise estimation units for estimating a first low and high band noise values; a first low and high band soft threshold processing units for forming a first low and high band noise reduction signals according to the first low and high band noise values; and a first inverse wavelet transform unit for performing an inverse wavelet transform on the first low and high band noise reduction signals. The noise reduction device and the noise reduction method can reduce or remove a noise in the luminance signal.

Description

【Technical field】 [0001] The present invention relates to a noise reduction device and method, in particular to a noise reduction device and method for a luminance signal. 【Background technique】 [0002] In analog TV, a composite video signal includes a luminance signal (Y) and a chrominance signal (C). The comb filter is usually used to separate the composite video signal into a luminance signal and a chrominance signal, and the process of separating the luminance signal and the chrominance signal is called Y / C separation (Y / C separation). [0003] In analog TV, it is very important to reduce the noise in the luminance signal. Generally speaking, the filter is used to reduce or remove the noise in the luminance signal. However, the filter cannot reduce the noise adaptively. More clearly In other words, when the effect of reducing or removing noise is strong, the luminance signal will also be destroyed, that is, the image including the luminance signal may be blurred; relat...

AI Technical Summary

Problems solved by technology

[0003] In analog TV, it is very important to reduce the noise in the luminance signal. Generally speaking, the filter is used to reduce or remove the noise in the luminance signal. However, the filter cannot reduce the noise adaptively. More clearly In other words, when the effect of reducing or removing noise is strong, the luminance signal will also be destroyed, that is, the image including the luminance signal may be blurred; relatively, when the effect of reducing or removing noise When very weak, the noise will still exist and affect the luminance signal

In short, filters cannot reduce or remove noise based on its strength

[0004] Therefore, solutions need to be proposed to avoid the above-mentioned problem of not being able to reduce or remove noise according to the noise intensity

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