Originally Posted by davidfor
There are two parts to this.
The Kobo devices don't actually use the cover image that is inside anepub. It generates the first page of the book and uses that. In general, this is just the cover image, but it can be more. So, exactly what the cover images used is based on the formatting for the first page. If the image gets stretched over the full screen, that is what you will see. So, what you get depends on how that first page is laid out. Calibre does have some options for changing this during a conversion, but I haven't played with them recently.
There is a second part is that the Kobo saves the cover images in different sizes depending on firmware level. For pre-2.x.x, it was 600*800 so it covered the whole screen. For 2.x.x, it saves it as 355*530. It then displays this image when sleeping or power off. There is also an option in the to stretch this image to cover the whole screen. If it isn't stretched, then the image sits in the middle of the screen with space around it.
One thing, the sizes above are for the Touch, I don't know if the Glo is storing images as different sizes. If someone wants to have a look, I can tell you what to do.
Changing the metadata for books in the calibre library requires a removing and sending the books to the device again. This isn't likely to change. But the only metadata that you can see on the device is the title, author and description.
But, the shelves are different. If your calibre preferences have metadata management set to automatic, and the appropriate settings on the driver (column name for shelves and whether to create them), books will be added to the shelves the next time calibre does a sync.
Thanks a lot for the detailed response. I guess I'll just have to reload some of my books.
As for the cover image, how do I find out which of the two is the issue? For one of the books that I have the cover problem with, I tried opening it in Calibre, and the very first page is the cover, nice and big.
Also, I do have a Glo, how would I go about checking if it does store images at a different size?