Scan base resolution in Page namespace seems to be based on the resolution of the first page of the DjVu file. This causes unexpected effect of unnecessary lowering resolution of scans used for other pages when the first page resolution is for some reasons much lower than resolution of other pages.

Example:

• random page from a book with low-res title page https://test2.wikipedia.org/wiki/Page:Drog%C4%85_czwartak%C3%B3w_od_Ostrowca_na_Litw%C4%99_%28test_file%29.djvu/126
• same page from the same book with title page scaled up (artificially increased resolution) https://test2.wikipedia.org/wiki/Page:W%C5%82adys%C5%82aw_Orkan_-_Drog%C4%85_czwartak%C3%B3w_od_Ostrowca_na_Litw%C4%99.djvu/126

Note: the underlying page (#126) remains unchanged.

Necessity of scaling up here seems to me to be an ugly workaround, and IMO this problem should be fixed in ProofreadPage.

Note: because of various errors or damages, book scans used in Wikisource are sometimes combined (as ProofreadPage is oriented to use a single DjVu file for a single book) from various sources offering various resolution scans.