writing to fild on another server

I have a web server and an images server. My web server doesn't have enought space for the images, hence the images server. I have to download properties from a realty database hourly and the data goes in to a db on my webserver while the image needs to be taken from a MSSQL db and written to the images server as an actual .jpg or .gif file. Fopen, however, won't let me write using the http protocol. How can I open and write files between servers? Thanks!