I found a program called "Dual Wallpaper" that allows me to stretch pictures across monitors.
However my monitors are different dot pitches (the one on the left is 24" 1920x1200, and the one on the right is 25" 2560x1440). As you can see, the resulting image is not aligned.
Is there a program that will do what "Dual Wallpaper" does, but accounting for the different pitches, hence aligning the image across monitors?