Software to Digitize Graphs

I really doubt if anything like this is out there. From the resolution of the graph depicted, it looks like you could "eyeball" the x and y values. While being rather time-consuming, I can see no other way to do this.

On the other hand, I am also sure that an algorithm could be devised to "plot" the x/y values using scanning hardware. It is concieveable that someone has done this, but obtaining the software, (CIA, FBI, etc.) would most likely cost you a "pretty penny" if you could get it at all.

It can be done using a GIS program - but that may not be cost effective if you buy a program.

Search for curve fitting programs. They do allow digitizing by mouse.

You could also use a digitizing pad/ table and a stylus/cursor.

DigitizeIt: http://www.digitizeit.de/

Thanks for your suggestions. I was able to obtain a GNU licensed one from "digitizer .sourceforge .net" . Its free and works great!

I just published a "HowTo" on ResearchGate, explaining how to use 3gdata to extract data from a graph, then convert the data to a mathematical function using Eureqa. This is only one of many tools available. Although I focus on a Linux environment, the 3gdata application is available as a Windows executable. Eureqa is a Windows application that runs wonderfully under Wine. There are a number of other tools out there that do the same trick. Drop me a private message, and I will send you the HowTo.

Look for a free program called WinDig25. Works like a charm.