Median filter

The calculator below processes the loaded image with a median filter. The calculator allows you to set the size of the filter kernel - 3x3, 5x5, or 7x7. A median filter is usually used to remove "noise" from an image. You can read more about how the median filter works under the calculator.

Median filter

Kernel size3x3 5x5 7x7

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Median filter

For each processed pixel of the source image

• calculate the luminosities of the neighbor pixels of the filter kernel (a square area that includes the processed pixel)
• sort the luminosities in the numerical order
• assign the median value (the value from the middle of the array) to the processed pixel in the resulting image

The median value is considered to be a more reliable "average" value for the color of the area than the actual average value since it is not affected by a random "noisy" pixel with a very different luminance value. And since the new pixel value is one of the existing values ​​in the area, the use of this filter does not give unrealistic pixels on sharp color transitions at the boundaries of objects.