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; import android.graphics.RectF; public class Main { public static Bitmap roundCorner(Bitmap src, float round) { int width = src.getWidth(); int height = src.getHeight(); Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(result); canvas.drawARGB(0, 0, 0, 0); final Paint paint = new Paint(); paint.setAntiAlias(true); paint.setColor(Color.BLACK); final Rect rect = new Rect(0, 0, width, height); final RectF rectF = new RectF(rect); canvas.drawRoundRect(rectF, round, round, paint); paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); canvas.drawBitmap(src, rect, rect, paint); return result; } }