segmentation of an image

I want to segment an black and white leaf image for getting leaf diseases.I want to segment this image to this form. Please someone help.

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

https://www.mathworks.com/matlabcentral/answers/?term=tag%3A%22leaf%22

[KALYAN ACHARJYA]

Please do us a favor to provide details, so that you may get get exact helps (specially its quite hard to comment on segmentation method, without seeing the images)?

[Rik]

This new question looks like a response.

[KALYAN ACHARJYA]

From the first image, you are expecting to get 2nd one, right?

[Sajitha K.N.]

Yes.I want to remove that white back ground only.

[Rik]

Have you tried to invert, use imclose, invert again and use that as a mask?