I created a YouTube video showing how you can quickly extract the stress-strain data from an image using the new tool in MCalibration. I have personally had to do this enough times that I wanted an accurate and quick tool for it. If you watch the video you will see how to select a small number of data points and then use cubic splines to make the extracted data smooth.
There are many other tools that can also be used to extract generic data from a scanned image, but we created this tool in order to make quick and easy to get data from a report or journal article into MCalibration. The tool works great and I recommend that you give it a try if you ever need to extract stress-strain data from an image to raw data that you can use for material model calibration.