Plot Digitizer 2.4.1 Description:
Plot Digitizer is a Java program used to digitize scanned plots of functional data. Often data is found presented in reports and references as functional X-Y type scatter or line plots. In order to use this data, it must somehow be digitized. This program will allow you to take a scanned image of a plot (in GIF, JPEG, or PNG format) and quickly digitize values off the plot just by clicking the mouse on each data point. The numbers can then be saved to a text file and used where ever you need them. Plot Digitizer works with both linear and logarithmic axis scales. Besides digitizing points off of data plots, this program can be used to digitize other types of scanned data (such as scaled drawings or orthographic photos). Plot Digitizer includes a special "semi-auto" digitizing feature. For plotted data that trends from left to right, you can simply indicate what data you want digitized with a thick paint brush and the program will automatically sort out grid lines, noise, etc, and will attempt to digitize the line for you. This feat is accomplished with the help of the open source autotrace image vectorization program (version 0.31.1). Currently this feature is available for Linux, MS Windows, and MacOS X running on x86 architectures, but if you are willing to port the autotrace program yourself, it could be made to run on other platforms. Will the auto-digitizing feature digitize any plot? Short answer: no. Long answer: The auto-digitizing feature works best with black and white, 300 dpi images of continuous data which does not run vertically (vertical lines give it fits), does not repeatedly cross other data lines, is not close to and parallel to grid lines, is not extremely noisy and which does not have plot symbols. After using the program a while you begin to learn what it can and can't auto-digitize. However, even in cases where it doesn't auto-digitize the entire line, you can sometimes do a piece of it automatically, then manually digitize a piece, and then do another piece automatically, etc. I've found this feature to be pretty useful on digitizing plots of experimental test time histories, but your mileage may vary.