jTechDig is described as 'Software tool written in Java for digitizing data from an image of graph or plot. jTechDig can import images from .gif, .bmp, .png etc. files. After mapping of the coordinates system the data can be digitized manually by clicking the mouse' and is an app. There are more than 10 alternatives to jTechDig for a variety of platforms, including Windows, Linux, Mac, Web-based and Self-Hosted apps. The best jTechDig alternative is WebPlotDigitizer, which is both free and Open Source. Other great apps like jTechDig are Engauge Digitizer, Plot Digitizer, g3data and PlotDigitizer.
Graphreader is a simple browser-based tool for extracting numerical values from images of graphs and plots, then exporting the data into CSV files.
Graphreader is the most popular Self-Hosted alternative to jTechDig.
