BitmapUtils.java

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;

public class BitmapUtils {
  private BitmapUtils() {
  }

  public static Bitmap padBitmap(Bitmap bitmap, int borderSize) {
    Bitmap bmpWithBorder = Bitmap.createBitmap(
        bitmap.getWidth() + borderSize * 2, bitmap.getHeight() + borderSize * 2, bitmap.getConfig());
    Canvas canvas = new Canvas(bmpWithBorder);
    canvas.drawColor(Color.TRANSPARENT);
    canvas.drawBitmap(bitmap, borderSize, borderSize, null);
    return bmpWithBorder;
  }
}