How to segment all the white dot automatically(binary mask)? Any suggested approach?

[Guillaume]

It's possible that you can't do anything about it, but first I would look at the image acquisition setup to improve contrast and sharpness.

It would make the image processing easier.

Answer 1

[Stalin Samuel]

http://www.mathworks.in/company/newsletters/articles/the-watershed-transform-strategies-for-image-segmentation.html

[TAY]

I have try watershed before but it didnt work well the mask created have some object connected