tengo unListView con imágenes de contacto y nombres o números. Ahora quiero redondear las esquinas de esta imagen de contacto.

public View getView(final int position, View convertView, ViewGroup parent) {
    View row = convertView;
    UserHolder holder = null;
    Log.d("main", "pos:" + "" + position);

            if (row == null) {
        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);
        holder = new UserHolder();
        holder.Name = (TextView) row.findViewById(R.id.name);

        holder.Number = (TextView) row.findViewById(R.id.number);

        holder.img=(ImageView) row.findViewById(R.id.image);


        Typeface face=Typeface.createFromAsset(context.getAssets(),"helve.ttf");

        holder.Name.setTypeface(face);
        //holder.Number.setTypeface(face);

        //bit = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);     
       //

        //holder.img.setImageBitmap(getRoundedCornerBitmap(bit, 40));

        row.setTag(holder);
    } else {
        holder = (UserHolder) row.getTag();
    }
    User user = data.get(position); 

    holder.Name.setText(user.getName());
    holder.img.setImageBitmap(user.getbi());
    //holder.img.setImageBitmap(roundCornerImage(BitmapFactory.decodeResource(user.getbi(), R.drawable.ic_launcher),60));
    holder.Number.setText(user.getNumber());




    // Give Different Back Ground To List View---------------------------------------------

    if ((position % 2) == 0) {
        row.setBackgroundResource(R.drawable.list_dark);
    } else {
        row.setBackgroundResource(R.drawable.list_light);
    }




    Log.d("main", "pos:" + "" + position);

    return row;

}



static class UserHolder {
    TextView Name,Number;
    ImageView img;

}

¿Cómo puedo agregar esquinas redondeadas a esta imagen? Estoy un poco confundido sobre qué tipo de cambio tengo que hacer.