Sending an image without the internet, over amateur radio.... (an okra blossom):
http://John1126.com/share/20241218-MFSK128X2-okra-160px.mp3
That was using MFSK128x2.

The same image in a faster operating mode (MFSK128x4), about double the speed, taking about half the time to send and receive:
http://John1126.com/share/20241218-MFSK128X4-okra-160px.mp3