# How to digitize an image graph to excel data? [duplicate]

I'm trying to compare my model results with an experiment. I want to overlap the model curve with experiment curve from a paper.

What are my options for digitizing the graph from an image in the pdf paper to excel data?

• You could also try to reproduce the graph/results from the paper in question by obtaining the original data. – bdeonovic Apr 22 '14 at 19:30

I tried to post this as a comment, but it was much too long (because it has lots of links).

I'll try to make it a little more post-like than the comment was.

Some links (several R related, but a number of other tools are in the list):
Digitizing plots
Digitizing jpeg graphs
Converting plots to data (i)
Converting plots to data (ii)
Getting data from figures in published papers
Digitize graphs with multiple point sets
Digitizing data from old plots
How to digitize plots
Wikipedia: Converting scanned graphs to data

A google search for "digitize graph" brings up several potential solutions.

What is best depends on what tools you are already familiar with and what level of automation vs. fine control that you want. I personally would load the graph into R then use the updateusr function in the TeachingDemos package along with the locator function to find the coordinates of points, but others may prefer other workflows.