99 - What is Non-local means (NLM) denoising filter?

Noise is an unfortunate result of data acquisition and it comes in many forms and from many sources. For scientific images (e.g. microscope, MRI, and EBSD),Gaussian noise arises from electronic components including detectors and sensors. In addition, salt & pepper noise may also show up from analog to digital conversion errors. Therefore, image denoising is one of the primary preprocessing operations that a researcher performs before proceeding with extracting information out of these images.

This tutorial explains the non-local means (NLM) filter and its use in Python. NLM filter is especially recommended to denoise CT, uCT, and MRI images.

[ewang]

WOW, so far NLM is the best filter introduced in this series, I like your video by the way, thanks

[awaisnawabi]

Hi,
Could you please guide me, if I want to do denoising the cell's images and after that I want to use model for segmentation. There are different types of denoising filters. So which type of denoising I use?

[vladimirrakonjac]

Hi, do you have any idea if is there an implementation of the Bilateral Filter for OpenGL through GPU and Shaders? Mobile phone real-time game is the subject of usage.

[ayserumeysamohammed]

Hi, a killer question: how do you choose a filter for a specific problem? e.g. you state that NL means works well with CT images. What about detecting an object in water?

[stenseenonwuliri]

Can these filters denoise colored images because i noticed all your sample images are black and white images. My images are microscopic thin blood smear images and whenever i use any of the filters, it returns a black and white image

[rajnikyadav]

Hello Sir, can you please send me the link of this NL- Means paper

[vigneshsrinivasan]

Why did you have to do np.mean while using estimate_sigma?

[puritynow]

Hello Sir. How can I write the code to denoise a bunch of images in a directory

[natashabhandari]

Can u send the video for dynamic non local mean filter

[younesshokoohi]

thanks for this tutorial . can you explain and implement Residual Unet in a tutorial please?