Adobe Photoshop enables a wide range of image-modification techniques that would otherwise be impossible in-camera, and among these is the capability to merge or combine two different photos, either ...
It’s fairly easy to blend two images in GIMP. All you have to do is: Open the two Images in GIMP. Blend the images using layer opacity/blend mode/layer mask. Export the resultant image as JPEG/PNG.
You may need to combine pictures from time to time but want a way to do it without the use of expensive software. You don't have to fork out a large amount of dollars just to purchase a simple image ...