Bitmap缩放到指定的大小

public  Bitmap zoomImage(Bitmap bgimage, double newWidth,                                   double newHeight) {        // 获取这个图片的宽和高        float width = bgimage.getWidth();        float height = bgimage.getHeight();        // 创建操作图片用的matrix对象        Matrix matrix = new Matrix();        // 计算宽高缩放率        float scaleWidth = ((float) newWidth) / width;        float scaleHeight = ((float) newHeight) / height;        // 缩放图片动作        matrix.postScale(scaleWidth, scaleHeight);        Bitmap bitmap = Bitmap.createBitmap(bgimage, 0, 0, (int) width,            (int) height, matrix, true);        return bitmap;    }