Losing Old Covers

[@emonashalom]

I'm quite sure Calibre use to keep the original book covers of the book and then add a new one to it, if it was edited.
My K4PC would open up 1st, with the book cover I added, then the original.
I have edited about 1000 of my books in it, most of which have 2 covers, and I want to keep both.
I don't know after which update, but now it seems to replace the cover.
Is there an option to which I can choose to keep original metadata too?

[dwig]

For performance reasons, calibre does not display either the cover or the metadata that is in the book. Instead, it uses a separate cover file stored beside the book and metadata stored in calilbre's own database. The cover file and the database metadata are extracted from the book when the book is imported into cablire's library so initially they match the contents of the book. Any edits in calibre are to its copies and not the the book itself unless you take special steps to inject the updates and changes into the book itself.

Many ereaders also avoid displaying the book's internal cover until the book is actually opened. Again for performance reasons, they use a separate cover file. Many of these readers won't extract a cover from an imported book and rely instead on the download/sideload service to provide a separate cover file. When calibre provides such files it uses its separate cover file and not the one actually in the book. Again, if you have not taken steps to inject a new cover into the book the external cover file and the internal file in the books won't match so you'll see one cover in the book list and another when you open the book for reading. If you have calibre convert formats when syncing with your device the updated cover will be used for the converted file, deleting the old cover. With some formats, other automated update functions can be configured to update cover and metadata during sync without actually running the book through a conversion process.

[eschwartz]

That only happens when the original cover was not properly marked as a cover image. For example, the MOBI format simply doesn't support cover metadata at all (the Kindle will simply assume the first image in the book is the cover image).

calibre has always tried to determine the existing cover and replace it. The situations where it fails, and keeps both, is regarded as a bug (which cannot be fixed as it requires human-level intelligence to make that judgment call).

...

If you want to keep both cover images, your best bet is to use the Edit Book feature and add one cover as a cover image and the other as the first "page" in the book.

[@emonashalom]

Originally Posted by eschwartz

That only happens when the original cover was not properly marked as a cover image. For example, the MOBI format simply doesn't support cover metadata at all (the Kindle will simply assume the first image in the book is the cover image).

calibre has always tried to determine the existing cover and replace it. The situations where it fails, and keeps both, is regarded as a bug (which cannot be fixed as it requires human-level intelligence to make that judgment call).

...

If you want to keep both cover images, your best bet is to use the Edit Book feature and add one cover as a cover image and the other as the first page" in the book.

eschwartz;
you were right, it appears that the original never used the image as a cover, so the fault lies in my books, not Calibre.
& the solution works too ☻
Merci beaucoup!

[@emonashalom]

Originally Posted by dwig

For performance reasons, calibre does not display either the cover or the metadata that is in the book. Instead, it uses a separate cover file stored beside the book and metadata stored in calilbre's own database. The cover file and the database metadata are extracted from the book when the book is imported into cablire's library so initially they match the contents of the book. Any edits in calibre are to its copies and not the the book itself unless you take special steps to inject the updates and changes into the book itself.

Many ereaders also avoid displaying the book's internal cover until the book is actually opened. Again for performance reasons, they use a separate cover file. Many of these readers won't extract a cover from an imported book and rely instead on the download/sideload service to provide a separate cover file. When calibre provides such files it uses its separate cover file and not the one actually in the book. Again, if you have not taken steps to inject a new cover into the book the external cover file and the internal file in the books won't match so you'll see one cover in the book list and another when you open the book for reading. If you have calibre convert formats when syncing with your device the updated cover will be used for the converted file, deleting the old cover. With some formats, other automated update functions can be configured to update cover and metadata during sync without actually running the book through a conversion process.

dwig, thank you very much for the explanation!
Now I know how it works too