I have scanned about 80 pages into gray scale pdf (image format). The end size of the file is about 70MB, which is very huge.
Now I am looking for a method to convert the grayscale image-based PDF file into a simple black/white text-based PDF file.
I have done many attempts with
gs but with no success (only a few percent recovery).
If any expert has some idea, kindly let me know.