How to draw the bounding box around the apple

I am new in Matlab, my task is to draw the bounding box around the apple, plz help me in this task.

Answer 1

[Image Analyst]

Very easy. Just use color segmentation. I have several demos in my File Exchange:

http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

If the apple has irregularities on the edges after segmentation, you can use activecontour() as shown in my attached demo to smooth the outline. Or else you can blur the color channel image before you threshold it.