Java tutorial
//package com.java2s; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PorterDuff; import android.graphics.PorterDuffXfermode; import android.graphics.Rect; public class Main { public static Bitmap toRoundCorner(Bitmap bitmap) { int height = bitmap.getHeight(); int width = bitmap.getHeight(); Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(output); final Paint paint = new Paint(); final Rect rect = new Rect(0, 0, width, height); paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); //paint.setColor(0xff424242); paint.setColor(Color.TRANSPARENT); canvas.drawCircle(width / 2, height / 2, width / 2, paint); paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); return output; } }