SCaVis can be used to easily convert between different units of measurement. Simply start SCaVis IDE and select [Tools]→[Unit conversion].
Read more in unit_convert how to access this tool in Java/Jython programs.
Use SCaVis to extract data points from image and save them into a file. Assume you have a image “example.gif” which shows some plot. You can open any image in the format PNG, JPEG or GIF. Open this image as:
You will see a windows with the image:
Now perform a calibration of X and Y axis. Select a X-range, say between 0 and 6, and type there numbers in the field X0 and X1. The use the mouse and drag the cursor along the X axis between 0 and 6. As you drag you will see a red line spanning 0 and 6.
Then calibrate the Y-axis. Select a Y-range, type it in the window to the left of the window (Y0 and Y1). Then use the mouse to draw a blue line between selected range along Y-axis.
Once the calibration is complete, start clicking with the mouse on the data line. You will see green crosses. Then select “Save data”. Data will be written into a file “example.gif.unknown” in the same directory.