Howtosignalprocessing
- How does the median filter work?
- Why median filter is better than average filter?
- What are mean and median filter compare their performance?
- How median filtering is used to reduce image noise?
How does the median filter work?
The median filter works by moving through the image pixel by pixel, replacing each value with the median value of neighbouring pixels. The pattern of neighbours is called the "window", which slides, pixel by pixel, over the entire image.
Why median filter is better than average filter?
Since the median value must actually be the value of one of the pixels in the neighborhood, the median filter does not create new unrealistic pixel values when the filter straddles an edge. For this reason the median filter is much better at preserving sharp edges than the mean filter.
What are mean and median filter compare their performance?
The median filter is also a sliding-window spatial filter, but it replaces the center value in the window with the median of all the pixel values in the window. As for the mean filter, the kernel is usually square but can be any shape. An example of median filtering of a single 3x3 window of values is shown below.
How median filtering is used to reduce image noise?
The median filter is also used to preserve edge properties while reducing the noise. Also, the smoothing techniques, like Gaussian blur is also used to reduce noise but it can't preserve the edge properties. The median filter is widely used in digital image processing just because it preserves edge properties.
