Data Loss in Spatial Referencing (imref2d)

I had some questions about spatial referencing of two images. So I have two images of the same size (1200X1600) each image has a scale bar and an associated value of what the scale bar represents in the real world. The two images both have different magnifications so the scale bar length(pixel length) and associated value is different. So I made a program that gets the scale bars pixel length and since it tells me the real world dimensions I have the pixel/realworld units. Now I'm using that value to change the x and y real world extent with imref2d (obtained by multiplying the x and y pixel dimensions by the realworld per pixel ratio). So I have the two images and a reference for each. I then use imshowpair('image1','reference1','image2','reference2','InitialMagnification','fit') So at this point I have the images overlapping each other so my goal is to align the overlapping images (which I've already figured out how to do that) but my question is in doing this is there any loss of data? I'm trying to justify me using this as apposed to getting the ratios and actually resizing the images and then overlaying them on top of each other to align them (which seems to have significant resolution decrease for one of the images which makes things difficult) I'm not sure if using spatial references would alleviate this problem or not.

Thanks!