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Digitizing data from old figures with ImageJ

Following on this earlier post concerning the retrieval of data from figures in published papers with R, here is a method for doing the same with ImageJ. This is a freely available program that should run on Windows/Mac/Linux, just like R. To extract data points from a figure, you’ll need the Figure_Calibration plugin developed by Frederic V. Hessman, available here. Download the Figure_Calibration.class file from that page and save it to your ImageJ/plugins/ directory. Then load up ImageJ.

[caption id=”attachment_1051″ align=”aligncenter” width=”400″ caption=”The example figure that we wish to retrieve data from. We can use … Continue Reading

Digitizing data from old plots using ‘digitize’

The June 2011 issue of The R Journal contains an article on the R package digitize (link to pdf) by Timothée Poisot. This might prove to be a handy tool if you occasionally find yourself needing to retrieve data points from figures in old articles for which you don’t have the raw data. There are a number of other stand-alone software tools to accomplish this same task, such as PlotDigitizer, DataThief, or TechDig (good luck finding that last one). These other programs all work, but I use them so rarely … Continue Reading