android 图片转 圆形和圆角矩形

android 图片转 圆形和圆角矩形，比较高效的方法
圆角矩形：
int w = getWidth();
        int h = getHeight();
        Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        Paint paint = new Paint(1);
        paint.setColor(0xff000000);
        RectF rectf = new RectF(0F, 0F, w, h);
        canvas.drawRoundRect(rectf, cornerRadius, cornerRadius, paint);
        return bitmap;

圆形：

int w = getWidth();
        int h = getHeight();
        Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        Paint paint = new Paint(1);
        paint.setColor(0xff000000);
        RectF rectf = new RectF(0F, 0F, w, h);
        canvas.drawOval(rectf, paint);
        return bitmap;