Slow Scan Television or SSTV is a method of transmitting pictures on a narrow voice channel. While it is used primarily by hams, pirate radio operators occasionally transmit pictures on shortwave by this method. Regular amateur radio SSTV activity is centered on 14230 kHz.
The SSTV signal can be decoded from SSB reception by running the audio output from the receiver to a PC sound card, and using software designed to convert the signal to an image. In a pinch, a microphone connected to the sound card can be held up to the receiver's speaker. A decent, free software package for transmitting and receiving SSTV is MMSSTV.