finding the number of grains in a microstructure image of a material

How is it possible to detect the irregular boundaries of grains alone eliminating imperfections(in the microstructure) which are not taken as grains.correspondingly getting the no of grains in the image.

[Walter Roberson]

Please post an image and indicate in it some sample imperfections that you want to eliminate.

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers