Image processing in the early days required large processing power, which meant that it was limited to those with big machines. the field of image processing likely evolved out of the space program in the 1960s. Early image processing evolved at NASA to extract the most information from low resolution images acquired during the Mariner Mars missions. The surface of Mars is low-contrast, and image processing was used to extract features. There was also the issue of residual images from previous “snapshots” affecting current images, and finally, transmission noise from Mars to Earth also had to be suppressed. Here is an image from the Mariner 4 mission.
This process relied on the analog video signals sent back from a spacecraft being transformed into digital data, which was achieved in 1963. By 1964, the NASA Jet Propulsion Lab’s IBM 7094 system had been programmed to process Ranger data. By 1969, image processing was fully incorporated into the data processing pipeline.
Put into context though, the 1964 Mariner Mars mission took 22 photos. The 200×200 images were transmitted at the speed of 8-1/3 bits per second.
So 200×200 = 40,000 pixels @ 8-bits = 320,000 bits to transfer. Divide this by 8-1/3 bits per second gives 38,415 seconds, which is 10.67 hours to transmit one image back to earth.