How do I plot the centers of stitched images?

I am following the Matlab Image Stitching tutorial on this page:

https://uk.mathworks.com/help/releases/R2017b/vision/examples/feature-based-panoramic-image-stitching.html

The code produces a stitched image. I would like to plot the centers of these photos on a 2D plot. So I use the following code to plot the x and y translation values in the transformation matrix tform:

%        [r r 0]
%tform = [r r 0]
%        [x y 1]

x = [];
y = [];
for n=1:numImages
    x(end+1) = tforms(n).T(3);
    y(end+1) = tforms(n).T(6);
end
figure
plot(x, y, '-o');

I expect the code to produce all of the points nearly on the same level just like the stitched panoramic photo, but what I get is:

When I use images that have more rotations, the points are sometimes plotted very far and the shape becomes not identical to the stitched photos (for example when stitching nadir photos). What am I doing wrong?

Update: I think that what I want to do is to apply tfoms on the centers of the photos (using imwarp), and not on the whole photo..

Answer 1

[Selva Karna]

imagesc(your_image)

Answer 2

[Gaurav Garg]

Hi Elie,

I would like to tell that the thing you are looking to do here is to have a perfect alignment.

However, when you register the images (Step 2) and then create the panorama (Step 4), the images are supposed to misalign a little bit. So, you can look at the Conclusion subsection and refer to the paper in references to improve the alignment of the panorama images.