Best way to remove unwanted region from image I am finding the techniques to remove unwanted regions (small dots) from image. I have an image that includes object and some unwanted region (small dots- see first image). I want to remove it. Hence, I use some morphological operator example 'close' to remove. But it is not perfect. Do you have other way to remove more clear (similar second image)? You can download example image at here
Looks like you are using Matlab. Try bwareaopen(I, N), where I is the original binary image and N is the estimated size of each unwanted connected region.

You can try edit bwareaopen for more details. Basically the algorithm tries to find the size of connected regions. Connected-component labeling with union-find algorithm is expected to get you there.