Hi can someone help me with this..

I have an image like this.

As you can see in the image the black spots are particles. I just want the particles alone on a white background. I tried various thresholding methods. They give me a Threshold of 145~146 but when I use that, the result is highly noisy and not even close to what I expect but when I use a value of 80 the result obtained is almost fine. But the value 80 was found by guessing and not by any code. Is there someone who can help me with this?

[Walter Roberson]

You sent me email. I am not able to reply to your email because your university blocks my provider.

[RAJESHWAR R]

sir I have messaged you again.

Answer 1

[Image Analyst]

I'd try imtophat() and imbothat() -- top hat and bottom hat filters. They basically do an opening or closing to erase the spot and then subtract it from the original. They're made for finding small spots on varying background. Give that a try and write back if you're getting nowhere.