A method of managing images over a wide-area network at a central server, the method comprising, at the central server: receiving an image file identifier for each new image file acquired by a microscope scanner at a remote storage location from the remote storage location via the wide-area network, wherein each image file comprises scanned slide data, and wherein the remote storage location has limited storage; storing the image file identifier and associated remote storage location for the new image file in a searchable central catalog in a common database, wherein the central catalog identifies both image files located at a central storage location and image files located at the remote storage location; adding a file transfer operation to a queue stored in the common database to transfer the image file by a file transfer program; after the file transfer operation by the file transfer program has transferred the image file from the remote storage location to the central storage location, by asynchronously accessing the image file on the remote storage location via an outbound connection, updating the central catalog to show that the image file is located at the central storage location, and sending a request message to a remote server at the remote storage location to delete the image file; receiving a request for image data from an image file, identified in the central catalog, from a viewing device via the wide-area network; if the requested image data is located at the central storage location, returning the requested image data from the central storage location to the viewing device; and, if the requested image data has not yet been transferred from the remote storage location to the central storage location, relaying the request to the remote server at the remote storage location, and relaying the requested image data from the remote storage location to the viewing device. receiving an image file identifier for each new image file acquired by a microscope scanner at a remote storage location from the remote storage location via the wide-area network, wherein each image file comprises scanned slide data, and wherein the remote storage location has limited storage; storing the image file identifier and associated remote storage location for the new image file in a searchable central catalog in a common database, wherein the central catalog identifies both image files located at a central storage location and image files located at the remote storage location; adding a file transfer operation to a queue stored in the common database to transfer the image file by a file transfer program; after the file transfer operation by the file transfer program has transferred the image file from the remote storage location to the central storage location, by asynchronously accessing the image file on the remote storage location via an outbound connection, updating the central catalog to show that the image file is located at the central storage location, and sending a request message to a remote server at the remote storage location to delete the image file; receiving a request for image data from an image file, identified in the central catalog, from a viewing device via the wide-area network; if the requested image data is located at the central storage location, returning the requested image data from the central storage location to the viewing device; and, if the requested image data has not yet been transferred from the remote storage location to the central storage location, relaying the request to the remote server at the remote storage location, and relaying the requested image data from the remote storage location to the viewing device.