DataThief

DataThief is a compact application designed to reverse engineer graphs and charts in order to extract the data used for generating them. The program allows you to interpret the graphs from screenshots, scanned documents and other images.

This tool is valuable for the users who need to grab the data from a chart in order to use it for their own charts and presentations. You can also use it for extracting the data table in order to analyze the data and calculate trends or average values.

In order to capture the data you need to calibrate the application and trace each line from the graph. Since this step determines the overall data accuracy, it is important that you take your time and even read the manual available on the developer’s website.

The program can define the coordinate system by using three points which should be sufficient for the vast majority of 2D graphs. For the graphs that do not have values for the points of origin, a four-point reference system is also available.

If the graph has multiple lines, you need to grab the data for each one by specifying its color, start and end. This app can follow the line and export the coordinates to a text file in order to use them in your projects.

The result can be fine-tuned by specifying the precision and the tolerance level in the Settings tab. You can also specify how many values you need to extract from the graph in order to perform an accurate analysis.

Using the application is quite easy after you understand how to calibrate it and trace the graphs. It supports the most popular image formats and the calibration features enable you to trace even low quality scans.

A useful feature is the ability to save the configuration to a profile in order to load it later when dealing with similar graphs. The advanced users also have the option to create functions and constants that improve the data extraction from certain images.

To sum up, DataThief is a flexible tool which can help you interpret the data from scanned or captured graph images.