How to find the area of the object in the center?

I have this image, and I am trying to find the area of the object in the center. I tried finding the area using imageJ but I wasn't very accurate. Any help or guidance would be appreciated. Thanks in advance.

Answer 1

[Matt J]

impoly worked pretty well for me. The area in pixels was 1358238

h=impoly();
area=numel(h.createMask) % 1358238

[oshawcole]

Did you draw it manually using impoly?

[Matt J]

Yes.