: One of the most popular and long-standing utilities for extracting data points from image files (BMP, JPG, TIF, GIF, and PNG). It features a GUI that allows you to calibrate axes by selecting four points and then "grab" data points by clicking along the curve.
: Specifically designed to digitize X-Y scatter plots from pictures. It is frequently updated and used for basic 2D data extraction. plot-digitizer-matlab
: A modern app that handles various image formats and supports complex digitizations, including log-scaled, tilted, skewed, or polar plots. It can re-interpolate data to a specified sampling rate, which is useful for further analysis like surface interpolation. : One of the most popular and long-standing
: For a manual, code-based approach, you can use the built-in ginput function. A common workflow involves loading an image with imread , displaying it with imshow , and then using ginput to capture pixel coordinates and transform them into graph coordinates using a calibration algorithm . It is frequently updated and used for basic
Regardless of the specific tool, the process generally follows these steps: Scalar plot digitizer - File Exchange - MATLAB Central
: This tool uses an automated algorithm that can trace a graph from an initial point, picking the nearest point to the previously digitized one to speed up the process. Key Tutorials and Blog Resources
Several powerful MATLAB-based tools and blog resources exist for digitizing (extracting data from) plots in images. The most effective approach typically involves using specialized GUI tools from the MATLAB Central File Exchange . Top MATLAB Plot Digitization Tools