How do you find the centre of an irregular shape?

I am working on irregular shapes in an MRI scan. I would love to know the centre of different detected region in the image?

[Daniel Shub]

As it stands now, this isn't a MATLAB question. What formula are you trying to implement and what problems are you having?

[Jan]

How do you define "center"? It can be the center of mass (then the center is the mean of the coordinates, if the object has the same density in each point). Or it could be the mean of the coordinates of the border. Or the point with the minimal sum of distances to all points of the area measured along paths inside the area (interesting for concave objects).

Answer 1

[Image Analyst]

Segment your region so that you have a binary image, then run regionprops and ask for 'Centroid' or 'WeightedCentroid.' Your next step: run my BlobsDemo for an example/tutorial: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862