Ocr?

i DLed a copy of THIS:

http://newspapers.oceancitylibrary.org/Data/1970-1989/SentinelLedger/1972/02-1972.pdf

and was shocked - shocked! - to find that ^F could find pretty much everything I was looking for. how is that POSSIBLE? it's clearly a scan/image file, not some sort of text mockup.

is OCR really that advanced these days?

also, ^F is so FAST...it's hard to believe it's doing ANY sort of conversion on the fly. is the OCR done at time of scanning, and STORED somewhere in the "info" of the PDF? pick a common word like "sale" -- you can jump from one to the next with no appreciable "analysis" time in between.