Java tutorial
//package com.java2s; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Point; import android.graphics.PorterDuff; import android.graphics.PorterDuffXfermode; import android.view.Display; import android.view.WindowManager; public class Main { public static Bitmap punchAHoleInABitmap(Context context, Bitmap foreground, float x1, float y1) { Bitmap bitmap = Bitmap.createBitmap(foreground.getWidth(), foreground.getHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); Paint paint = new Paint(); canvas.drawBitmap(foreground, 0, 0, paint); paint.setAntiAlias(true); paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR)); float radius = (float) (getScreenSize(context).x * .06); canvas.drawCircle(x1, y1 - 450, radius, paint); return bitmap; } public static Point getScreenSize(Context context) { WindowManager window = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); Display display = window.getDefaultDisplay(); Point size = new Point(); display.getSize(size); return size; } }