It may happen to access a PDF file over the internet with a graph and no data available in numeric format..
this is an example from the European Parliamentary Research Service Blog:
The problem is that it is impossible to use the depicted data: you have to print the image, use a ruler, do the math and get some approximate value…. unless…
It works quite well and it is easy to use
Here some snapshot of the process to acquire data out of the proposed graph:
You have to define the type of graph and provide the axis so that the tool is able to do the math alone…
you highlight the point you want to capture…
and press the button to obtain..
and you can export data: It is now simple to assign the correct labels to the Bars, you can even do it directly in the tool
Now data is available for use it in your models, documents etc.