Hi, i need to find distinct object in binary image,plz help to do with matlab code

I enclose two images, one is origin

al image,next is binary image.I want this binary image to look closer as original image.plz help me sir.

[kaavya subramani]

I also enclose my processed image,u plz do further process to make it to binary image which looks similar to original image

[Walter Roberson]

Consider marking boundaries where the image changes rapidly rather than where it is bright or dark.

[kaavya subramani]

I tried boundary markings sir,but still i am getting same result,not distinct object.plz help me

[Walter Roberson]

http://www.mathworks.com/discovery/edge-detection.html