Shortwave Radiogram's are digital broadcasts of images, text and sometimes HTML files that are regularly broadcast on two shortwave radio stations, WRMI in Florida and WINB in Pennsylvania. The transmissions are produced and presented by Dr. Kim Andrew Elliott, and a schedule can be found on the Shortwave Radiogram website.
Over on his blog Jeremy Clark has been experimenting with receiving shortwave radiograms with an RTL-SDR and upconverter. To do this he notes the transmission schedule on the shortwave radiogram website, and uses SDR# and MultiPSK in MFSK mode to receive and decode the data. Jeremy's post explains the MFSK transmission mode and shows a few examples of radiograms that he's received including a video posted below showing live reception and decoding.