Bartlane system

The Bartlane system^[1] was a wirephoto technique invented in 1920 to transmit digitized newspaper images over submarine cable lines between London and New York. Named after its inventors Harry G. Bartholomew and Maynard D. McFarlane,^[2] it was the first digital imaging system ever invented.^[3][4] It was first used to transmit a picture across the Atlantic in 1921.^[5] Using the Bartlane system, images could be transmitted across the Atlantic in less than three hours.^{[clarification needed]} The images were initially coded with 5 gray levels, but this number was increased to 15 in 1929.^[2] At the transmitter, the pattern on the telegraph tapes were made using special printing devices and decoded into the image at the receiver using telegraph printers equipped with appropriate typefaces.^[6]

This system was also adapted with a photographic process in order to get more precise images in 1929, so that at the receiver the images were converted to a chemical medium.