Microsoft invented it? I recall working on a digital mapping system in the late 80&#x27;s that was very similar. We had a very large drum scanner that we used to scan paper maps and imagery at various scales. First we&#x27;d rectify the result, then we&#x27;d do a color reduction to both cut down the file size and to match the capabilities of the machines of the day. Next we&#x27;d slice the image up into 128x128 pixel tiles and assemble the result into a database of various scales that allowed a user to zoom, pan from map to map, overlay symbology, etc. At the time we were working with 300 MB drives, so we were very restricted and had to create specific databases that matched a user&#x27;s need.