android: get image dimensions without opening it

Actually, there is another way to solve this problem. Using the below way, we can avoid the trouble with file and URI.

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
ParcelFileDescriptor fd = mContext.getContentResolver().openFileDescriptor(u, "r"); // u is your Uri
BitmapFactory.decodeFileDescriptor(fd.getFileDescriptor(), null, options);

Pass the option to just decode the bounds to the factory:

BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;

//Returns null, sizes are in the options variable
BitmapFactory.decodeFile("/sdcard/image.png", options);
int width = options.outWidth;
int height = options.outHeight;
//If you want, the MIME type will also be decoded (if possible)
String type = options.outMimeType;