I want to know the answer to the following question:
Who developed the first systems to transmit slow-scan video?
All the background I'm provided with is that "Attempts at using normal telephony networks to transmit slow-scan video, such as the first systems developed by AT&T Corporation, first researched in the 1950s, failed mostly due to the poor picture quality and the lack of efficient video compression techniques.". Is that enough to answer the question?