This tool helps you read data points from a figure stored as an image.

Drop the image of the figure that contains the data points you want to measure. Once the image is loaded, the green horizontal and vertical rulers as well as the data point marker will appear on the top left corner. You can drag the rulers' body and their end points with the mouse to fit them to the axes. When the rulers are positioned, set their start and end values in the corresponding boxes and fix their position to avoid further displacements.

Use the green marker circle to drag to the data point you want to measure and then click on 'Save data point'. This will add the data point to the dataset and also show its coordinates on the Dataset list. You can display the collected data points on the figure by checking the box 'Display data'. Also, on the Dataset list you can remove individual data points. Once the data points are collected, you can download them in a CSV file by clicking on 'Download data'.

The control elements (a ruler's body, its end points, or the data marker) can be selected for more fine positional adjustments. Click on a control element to select it: once it turns red, the selected element can be moved around with the arrow keys (←, ↑, → and ↓). The arrows move the currently selected control element by 0.2 pixel.