Calculating the area inside a region of interest

Hello, I am getting fluorescent images with a hyper fluorescent area in the center of my image. I am trying to come up with an algorithm which it could calculate the area "inside" the rim that is shown in my images. The area does not follow a set shape, sometimes it's circular, sometimes elliptical and sometimes semi-rectangular. Any help is appreciated.

Answer 1

[Walter Roberson]

Create a bw version of it, true for the parts inside. imfill() that with the 'holes' option. Then either regionprops() that with the 'Area' option, or simply us sum(FilledImage(:)) to get the total number of pixels