What is Noise Reduction? Check This Detailed Post

Melissa Lee updated on Jan 05, 2024 | Home > Glossary and Terms

Noise reduction is commonly used for audio and images. With the development of internet technology and the multimedia industry, more and more people are talking to others online and making videos on their own. Thus, the need for noise reduction in these activities is increasing quickly. Then, what is noise reduction? Let's read the content below together.

Noise Reduction for Audio

Tape hiss is the common noise in audio. Four types of noise reduction are single-ended pre-recording, single-ended hiss reduction, single-ended surface noise reduction, and codec or dual-ended systems.

Check the commonly used noise reduction systems and tools below:

  • Dual-ended compander noise reduction systems: They have a pre-emphasis process applied during recording and then a de-emphasis process applied at playback.
  • Dynamic noise limiter (DNL): This audio noise reduction system was originally used on cassette decks. It was further developed into dynamic noise reduction (DNR) to reduce noise levels on long-distance telephony.
  • Software programs: In our daily lives, some software with noise reduction functions are commonly used, including digital audio workstations (DAWs) and audio editing software.

If you are an ordinary person and want to reduce the noise of your video or audio, you'd better choose software with noise-reduction functions. Audacity, Adobe Audition, and EaseUS RecExperts are good options.

Noise Reduction for Images

Images taken with digital cameras or conventional film cameras will pick up noise from a variety of sources. There are two main types of noises in images: one is Salt and pepper noise(impulse noise), and the other is Gaussian noise.

Noise Reduction for Images

The common techniques used in removing image noises are:

  • Chroma and luminance noise separation
  • Linear smoothing filters
  • Anisotropic diffusion
  • Non-local means
  • ...

In choosing the best way to remove image noises, you may consider factors like the available computer power and time available, whether sacrificing some real detail is acceptable, the characteristics of the noise, etc.

Noise Reduction vs Noise Rejection

Noise Reduction and Noise Rejection are two different things. Noise reduction is the process of removing noise from a signal. It can be seen as the recovery of the original signal from the noise-corrupted one, which may distort the signal to some degree. In comparison, Noise Rejection is to isolate an undesired signal component from the desired signal component.


After reading this article, you may have known some of the basics of noise reduction. You may share this post with more people and discuss your opinions with them. Just click the bars below to start sharing!


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Updated by Melissa Lee

Melissa is a sophisticated editor for EaseUS in tech blog writing. She is proficient in writing articles related to screen recording, video editing, and PDF file conversion. Also, she's starting to write blogs about data recovery, disk partitioning, data backup, etc.

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