This program works backward from output to data, converting graphed data to individual data points that you can use in various data-based programs.
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Engauge Digitizer is an open-source program designed to convert charts or maps provided as images into numeric data which can be exported as CSV and manipulated using Excel or other programs...
Manual digitization, as the name implies, involves going over a chart and manually placing enough points on it as to eventually have an adequate representation of it. In this scenario you need not worry so much about removing unwanted information from the image since you placing the points yourself anyway.
Automatic digitization is an option whereby the program will automatically hone in on a graph (or large segments of a graph), or you can outline a point on the graph and ask Engauge to hone in on all points that look like it. For the program to do these things correctly you need to eliminate all visual data that is not part of the graph or chart you are after. You can do this by using Engauge’s own filters, of which 2 (descretize and grid removal) are available. (You can also do a lot of cleaning up externally using an image editing program)...
