Aspect Ratio for Cover doesn't seem to get changed

[Caribou007]

Update: I found a solution. The problem is that after changing the metadata, you have to use Convert Books to save the changes. Otherwise the file that gets sideloaded to the e-reader will not be modified.

Devices:
Kobo Glo firmware v. 3.12.1
Calibre v. 1.48.0

What happens:
I used "edit metadata" to change the book cover, and the kobo glo displays the cover with white lines on two sides. "Preserve cover aspect ratio" is not checked in Calibre Preferences > Output / Calibre Device Configuration / KoboExtendedTouch Plugin Configuration.

More information:
I read that there is html within the ebook that may be relevant to this. I used "edit book" and looked at the xhtml file for the front cover, I didn't see any code referencing aspect ratio.

What do I have to edit to make the cover stretch to fit the screen?


Another problem:
Another ebook has a front cover which the Kobo Glo won't recognize as the cover. Is there a tag or some code I should be checking?

[davidfor]

As you are using the KoboTouchExtended driver, the books are being converted to kepub as they are sent to the device. For all other formats, the Kobo devices render the first page of the book and use that as the cover. For kepubs, an image in the book is marked as the cover and used. The extended driver attempts to find the cover image in the book and mark it. It does this based on the names and other properties of the images in the book.

The last bit is why some books sent as kepubs do not have a cover on the device. The driver cannot identify the cover, so it doesn't mark any image as the cover. Or the book doesn't have one.

For the white stripes problem, it depends on where you are seeing them. If they are there when you open the book, it is the code in the page. You need to modify the code to display the cover how you want.

For the cover displayed elsewhere, the Kobo devices resize the cover image extracted from the book to display. If the cover has the correct aspect ratio, no bars will be seen. But, if it is not, then it depends on where. The sleep screen will show the bars on the side. But, the covers shown on the home page or the library list shouldn't show any.

You can avoid most of this by using the "Upload covers for books" in the driver. This will send the cover when sending the book and resize them fit the screen.

Edit: It took me a while to type the above.

Yes, running a convert will update the cover. So will Polish Books and the Modify ePub plugin. How needed they are depends on the state of the book and whether the driver can find the cover.