Add feature to an existing Android Activity to annotate an Image

The job is to edit an existing activity with an ImageView (XML layout and class file provided) and add the capability to annotate the Image. The user should be able to choose between a circle or an arrow and draw it on the image. The user should be able to choose the outline color and an undo button to step back. There is some existing code which should stay unchanged as existing functionality should stay unchanged. Existing functionaly includes rotate image and delete image. I have attached the image for better understanding, any questions, please do ask beforehand. I have not included the action bar on top in the image I have attached. If the user has not deleted the file, the activity should delete the existing file and replace it with the annotated version. Of, course you will have the imagePath given for that. Please confirm : 1) Any demosntrable similar projects done? 2) Any questions about the requirement above before you begin working on it? 3) What approach will you follow, any use of existing libraries or dealing with Canvas etc directly Thanks