+/**
+ * Returns the real mime type of an image file.
+ *
+ * This depends on exif_imagetype() or getimagesize() to determine real mime types.
+ *
+ * @since 4.7.1
+ *
+ * @param string $file Full path to the file.
+ * @return string|false The actual mime type or false if the type cannot be determined.
+ */
+function wp_get_image_mime( $file ) {
+ /*
+ * Use exif_imagetype() to check the mimetype if available or fall back to
+ * getimagesize() if exif isn't avaialbe. If either function throws an Exception
+ * we assume the file could not be validated.
+ */
+ try {
+ if ( is_callable( 'exif_imagetype' ) ) {
+ $mime = image_type_to_mime_type( exif_imagetype( $file ) );
+ } elseif ( function_exists( 'getimagesize' ) ) {
+ $imagesize = getimagesize( $file );
+ $mime = ( isset( $imagesize['mime'] ) ) ? $imagesize['mime'] : false;
+ } else {
+ $mime = false;
+ }
+ } catch ( Exception $e ) {
+ $mime = false;
+ }
+
+ return $mime;
+}
+