Convert Image to Black and White

Convert Image to Black and White with this simple method

public Bitmap ConvertToBlackAndWhite(Bitmap sampleBitmap){
ColorMatrix bwMatrix =new ColorMatrix();
bwMatrix.setSaturation(0);
final ColorMatrixColorFilter colorFilter= new ColorMatrixColorFilter(bwMatrix);
Bitmap rBitmap = sampleBitmap.copy(Bitmap.Config.ARGB_8888, true);
Paint paint=new Paint();
paint.setColorFilter(colorFilter);
Canvas myCanvas =new Canvas(rBitmap);
myCanvas.drawBitmap(rBitmap, 0, 0, paint);
return rBitmap;
}