In the glory days of the old wire services, say the 1930’s, how were news photos transmitted? Was the ‘data’ sent over telegraph lines? Telephone lines? How was a 2-D picture encoded and transmitted using the linear media of the day?
I should say that I suppose the images were “scanned” in line by line, in one long sequence. So, a 200 X 300 dot picture would have taken 60,000 “bytes”. If this is correct, my questions are i) wouldn’t that have been awfully slow back then and ii) subject to lots of errors without some type of electronic monitoring?
The early ones were a sort of primitive fax, scanning the photo, sending it over the phone lines, then outputting it onto photographic printing paper with dots of light.
http://www.cycleback.com/newsphotohistory.html
http://www.historybuff.com/library/refwire.html
http://www.ap.org/pages/history/photos.htm