How to recompose a whole picture, with fragmented parts?

Question

I have a set of images, which are parts of a bigger image.

I would like the images to assembled as automated as possible, to recompose the whole picture.

How can I do that?

Please note that this is not pictures. I've tried Hugin and Autostitch, but here, I have a flat image and the softwares didn' worked as expected.

I have nearly 10x10 small images. All images have the same size, but parts of the bigger can appears on two pictures, that my overlapping a bit.

[Edit] To illustrate, my wish, here is a very simple example with a 2*2 picture :

I have 4 images (borders are not in the images, its for comprehension). The solution may detect automatically how to position each images, and produces the final image

[Edit2] A bit of background: the process, whatever tool it implies, is targeted to people that have low level of image editing skills (so I am!). Using some basic tools like autostitch is ok (if it works, which is not the case for autostitch). And most of all, paid software is not an option in my context. Using photoshop is then prohibited.

The process will be executed several times, by several users. The acceptable amount of time for the whole manual process (excluding potential computing time then) should be less than 10 minutes.

Answer 1

Do you have a program like GIMP, which allows you to create layers, and adjust their transparency?

Do you have the time to manually assemble this picture yourself, or is this some kind of academic exercise where you want to find the software that will automatically assemble for you?

Because the first thing that came to my mind, was importing each picture fragment into a Photoshop image. The first fragment you import you leave solid. Each subsequent image you import, you put on a new layer and make transparent... and move around until it lines up.

Unfortunately...

I would like to assemble the images to recompose the whole picture.

and

The solution may detect automatically how to position each images, and produces the final image

seem to be in conflict to a degree. The first implies you want to do this. The second implies you want software to do this for you. My solution satisfies the conditions of the first statement, but not the second.

EDIT - I removed the reference to Adobe Photoshop, which costs money, and replaced with GIMP (as well as a link to it) which is free.