/**
* 擷取圖檔檔案頭資訊
* @param in
* @return
*/
public static BitmapFactory.Options getImageOptions(InputStream in) {
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inJustDecodeBounds = true;
BitmapFactory.decodeStream(in, null, opts);
return opts;
}