Explain in detail about Median Filtering?
Median filtering is a nonlinear method used to remove noise from images. It is widely used as it is very effective at removing noise while preserving edges. It is particularly effective at removing ‘salt and pepper’ type noise. The median filter works by moving through the image pixel by pixel, replacing each value with the median value of neighboring pixels.
The pattern of neighbors is called the “window”, which slides, pixel by pixel over the entire image 2 pixel, over the entire image. The median is calculated by first sorting all the pixel values from the window into numerical order, and then replacing the pixel being considered with the middle (median) pixel value.
There are other approaches that have different properties that might be preferred in particular circumstances: – Avoid processing the boundaries, with or without cropping the signal or image boundary afterwards. – Fetching entries from other places in the signal. With images for 4 example, entries from the far horizontal or vertical boundary might be selected. – Shrinking the window near the boundaries, so that every window is full.