In Android, an ImageView is a rectangle by default. How can I make it a rounded rectangle (clip off all 4 corners of my Bitmap to be rounded rectangles) in the ImageView? >
This pure xml solution was good enough in my case. http://www.techrepublic.com/article/pro-tip-round-corners-on-an-android-imageview-with-this-hack/
EDIT
Here's the answer in a nutshell:
In the /res/drawable folder, create a frame.xml file. In it, we define a simple rectangle with rounded corners and a transparent center.
In your layout file you add a LinearLayout that contains a standard ImageView, as well as a nested FrameLayout. The FrameLayout uses padding and the custom drawable to give the illusion of rounded corners.