Once upon a time I used a product called "ReadIRIS". It worked to my satisfaction, but that was 5 or more years ago... couldn't tell you if they have kept it up-to-date.
I'll leave it to you to find it via Google
You're looking for OCR (Optical Character Recognition) software. There will be dozens of options available ranging from free to several hundred USD. It's a rather complex process from a software point of view, so you will probably end up getting what you pay for... but the free or cheap ones may still be adequate for your needs.