Replacing or Adding embedded MOBI cover

[Timboli]

I have a MOBI file that does not show a proper cover image, instead it displays some kind of textual made up one, perhaps care of some calibre feature.

Anyway, I managed to fix things after doing some research. The chief help was this old topic - Managing cover images in mobi/epub files

The solution was not readily apparent to me though, until I tried it.

I did not want to use the convert MOBI to MOBI method, as I wanted my source MOBI file to remain unchanged, cover image excepted, and conversion always changes something.

So anyway, for the sake of simplifying things for others, and also maybe having something I can find again at need, in case I forget the process, I am outlining the simple quick solution here, below.

1. Load your original MOBI file into calibre, and select it.
2. Click the Edit Metadata button.
3. In the Edit Metadata window, choose your method of Change cover ... Browse or Download, etc.
4. Click OK to save and close the Edit Metadata window.
5. Click the Save to disk button.
6. Delete your original MOBI file ... making sure you have a backup of course.
7. Reload the saved MOBI in its place.
8. Check the cover has been embedded, using the View button, which opens up the Ebook Viewer for the format you selected (MOBI).

That's it, worked a treat for me and was pretty much instant, so clearly no conversion occurred.

I started with a 359 kb MOBI file, and the fake cover was 10 kb. The image I wanted, was 15 kb, and the resulting saved MOBI file, was 365 kb ... which all adds up roughly, as the 10 kb being replaced by the 15 kb.

[kovidgoyal]

covers in mobi filesa re automatically updated when updating metadata, which happens whenever you export the file from calibre