Our recommended approach is to use our File API. If the file is stored on the DAQ station after it is produced you can simply use the Send File VI to upload it to the SystemLink server managing the station. You may also stream a buffer the image data to the server without having to save it locally first.
As Mark mentioned if you need to store the data I would recommend using the File API.
In addition, here is an example I put together that shows how to transfer an image as a tag and then show it in the web interface using a WebVI. It isn't intended for live streaming, but it could be used to periodically see the latest image.