The Interpolate/Extrapolate plug-in facilitates the linear interpolation of two images in a straightforward manner.
To get a better idea of what can be achieved with this plug-in, I took a look at the Grafica Obscura pages for examples. Additionally, I decided to test the plug-in's capabilities myself. One of the most interesting results I discovered was with a colored image and its grayscale version. I noticed that when extrapolating away from the grayscale image, the resulting image had an increased saturation that I found quite fascinating.
Overall, the Interpolate/Extrapolate plug-in offers a good range of options for image manipulation. I specifically enjoyed the freedom to experiment with different blending factors outside of the typical range. If you're looking to spice up your photo editing process, I highly recommend giving this plug-in a go.
Version 1.01: N/A