Finding Image MIME type - php

Question

I'm having no luck getting the MIME type of an uploaded image before that image is saved into a database. I've read books and dozens of web pages but cannot find an answer.
How can I determine the MIME type?
Here's the code I currently have. I've removed the various attempts at determining the MIME type:
$upload_dir = HOST_WWW_ROOT . "uploads/movie_pics/";
$image_fieldname = "movie_pic";
// Name the file uniquely
$now = time();
while (file_exists($upload_filename = $upload_dir . $now .
'-' .
$_FILES[$image_fieldname]['name'])) {
$now++;
}
// Insert the image into the movies_images table
$image = $_FILES[$image_fieldname];
$movie_images_filename = $image['name'];
$movie_images_info = getimagesize($image['tmp_name']);
$finfo = finfo_open();
$movie_images_mime_type = finfo_file($finfo, $upload_filename, FILEINFO_MIME);
finfo_close($finfo);
$movie_images_size = $image['size'];
$movie_images_data = file_get_contents($image['tmp_name']);
$insert_image_sql = sprintf("INSERT INTO movies_images " .
"(movie_images_filename, movie_images_mime_type, movie_images_file_size, movie_images_data) " .
"VALUES ('%s', '%s', %d, '%s');",
mysql_real_escape_string($movie_images_filename),
mysql_real_escape_string($movie_images_mime_type),
mysql_real_escape_string($movie_images_size),
mysql_real_escape_string($movie_images_data));
mysql_query($insert_image_sql)
or die(mysql_error());

Answer 1

From the manual page of finfo_file the example passes the const FILEINFO_MIME_TYPE to finfo_open, rather than finfo_file.
$finfo = finfo_open(FILEINFO_MIME);
$movie_images_mime_type = finfo_file($finfo, $upload_filename);

Answer 2

If you are sure you will only ever be dealing with images you can use the exif_imagetype().
The below code will compare a file to a particular IMAGE type. It then uses image_type_to_mime_type() to retrieve the file's mime-type using the image type stored in $image_type.
Example 1 (extracted from link above)
// if file is a GIF line below should return IMAGETYPE_GIF
$image_type = exif_imagetype('image.gif');
if ($image_type == IMAGETYPE_GIF) {
$mime = image_type_to_mime_type(); // will produce "image/gif" as String.
echo 'The picture is a gif, with a mime type of ' . $mime;
}
Do NOT use mysql_* for new code.
Also, it is advised to no longer use mysql_* functions for new code, as it has been deprecated. I would recommend looking into mysqli_* or PDO forms of MySQL querying.