ItemChecksum will display the MD5 or SHA-1 checksum of the specified item (picture or video).
ItemChecksum will allow you to view the MD5 and/or SHA1 checksum of any item (photo or video) in your Gallery. It does not have any theme integration, and instead must be accessed manually for each item you wish to view the checksum of.
For MD5 Checksum's, the URL is: http://www.example.com/gallery/index.php/itemchecksum/md5/ALBUM_ID_NUM/FILE_NAME
For SHA1 Checksum's, the URL is: http://www.example.com/gallery/index.php/itemchecksum/sha1/ALBUM_ID_NUM/FILE_NAME
The module will then search for the first file named "FILE_NAME" in the album represented by "ALBUM_ID_NUM" and display the corresponding checksum. In the event no such file exists, it will display a 0. In the event my KeepOriginal module is installed and active, ItemChecksum will first check for an original image and if found, display it's checksum instead of the fullsized image.
In addition to the above two URLs, this module module also contains an "album count" URL which will display the number of items in an album, excluding sub-albums. http://www.example.com/gallery/index.php/itemchecksum/albumcount/20
This module also supports the REST API. The following URLs will return REST-friendly SHA1 and MD5 checksums: http://www.example.com/gallery3/index.php/rest/itemchecksum_sha1/ITEM_ID#
This module may be downloaded from the Gallery forums here.
To install, extract the "itemchecksum" folder from the zip file into your Gallery 3 modules folder. Afterwards log into your Gallery web site as an administrator and activate the module in the Admin -> Modules menu.