Comics often have landscapes that span two pages. A two-page view could show the full picture. Mangas, read from right to left, would need the two pages merged from right to left: [-2-][-1-] Reproducible: Always An issue you would likely run into is mismatched pages. For example, the cover page should not be merged with the first page. Complicating matters is the fact that some comics may have alternate covers included. I do not think there is an easy where to deal with this. Because of this, you may need to include an option to manually offset which pages are merged.
If you are able to provide me with a few examples of comic archives with this format (email them to me, don't add them here), i can try and have a look and see what i can do for working out heuristics :) But yes, some things will likely need manual intervention, which is something i'll need to look at as well, though it isn't in the scope of this particular report (this would be covered under the Viewport task on the work board)