WebPlotDigitizer

扩展迷 | chrome插件 | 下载与安装教程（图文讲解，全网最详细）

Web based tool to extract numerical data from plot images or maps. Also includes simple distance and angle measurement tools.

Supports XY charts, bar graphs, polar plots, ternary diagrams and maps. Automatic extraction algorithms make it very easy to extract large number of data points quickly and accurately. Also allows sharing data with Plotly for visualization.

Check out http://arohatgi.info/WebPlotDigitizer for more details, video tutorials, user manual and blog.