Book cover won't show

[RonaldP]

I just added several books, and although it shows up in Caliber the cover for one of them does not show up on my Kobo. I have hundreds of books installed on the Kobo and this has never happened before.

I tried removing the book file from the Kobo and re-adding it from within Caliber. No joy. I then tried changing the cover to a different version of the same thing (slightly smaller),and re-adding it again. Again no joy. The cover just will not be displayed, not even with the text for the title as has happened in the past. Just a blank title page, and no thumbnail in the listing.

Anything I can do?

Ron

[theducks]

Assumes you embedded it properly (polish can update all internals).
Both the Image and the cover page must be so marked.
Also, the cover image needs to be of a supported encoding (not all JPEG are the same) for the device.

[RonaldP]

Not sure what I could do differently. The other 4 books procssed in Caliber at the same time were fine. As were the hundreds of other books in the library.

I thought of a problem with the jpg, which is why I deleted the cover image that came with the book and downloaded a different one from within Calibre. And I removed the book from the reader and reloaded it from Caliber.

What else can I try?

R.

[davidfor]

Originally Posted by RonaldP

Not sure what I could do differently. The other 4 books procssed in Caliber at the same time were fine. As were the hundreds of other books in the library.

I thought of a problem with the jpg, which is why I deleted the cover image that came with the book and downloaded a different one from within Calibre. And I removed the book from the reader and reloaded it from Caliber.

What else can I try?

What format are you sending to the Kobo device? And is the cover embedded in the book and showing as the first page? And what does the device actually show as the cover?

The questions are because the Kobo devices do different things with different formats. For epubs and PDF, it actually renders the start of the book and uses the first page as the cover image. For kepubs, it looks in the book for the image that is marked as the cover and uses that. If there is no image marked that way, then no cover is used. Fro comic book formats, the first image is used. For text and other formats that don't have associated images, no cover image is used.

Rereading the first post, you do say "blank title page". That suggests the book is an epub, and that the cover is not actually used in the book. If you open it in the calibre viewer, the first page is probably blank there. In this case, you need to add the cover to the book. The simplest way to do this is with Polish books. That has an option to add the cover. But, there are other ways to do this depending on the control you want. Once you have added the cover, you will need to send the book to the device again.

The other thing you can do is configure the driver to send the cover with the book. This means that calibre generates the cover from the library (which might not be what is in the book) and puts that on the device for it to use. This can produce a better result but that is in the eye of the beholder. You can also use my Kobo Utilities plugin to send covers for books already on the device. That can just replace a few covers without otherwise updating the books.

[RonaldP]

I will try these things, but I am quite mystified why it would be a problem for this specific book and not for any others from the same sources. It is indeed an epub, a commercial distribution.

I used Calibre to locate and download another cover, a jpg. Both the original and this one show up fine within the Calibre app itself, but not in the ebook viewer. The viewer shows a text cover (name, author, publisher) but not the jpg. There is no text cover showing up in the Kobo, just a blank page.

[davidfor]

Originally Posted by RonaldP

I will try these things, but I am quite mystified why it would be a problem for this specific book and not for any others from the same sources. It is indeed an epub, a commercial distribution.

I used Calibre to locate and download another cover, a jpg. Both the original and this one show up fine within the Calibre app itself, but not in the ebook viewer. The viewer shows a text cover (name, author, publisher) but not the jpg. There is no text cover showing up in the Kobo, just a blank page.

That is what I expected. The cover and the first page of the book are separate things. I tend to assume the first of an ebook is the cover, but, some publishers do not. They might include the cover image in the book, but, don't link it to a page. And some will use a nice cover in the store, but, put a simpler cover inside the book and on the first page. Penguin is a publisher that tends to do these.

Another issue is that, for various reasons, books on Kindles can have the cover as the last page. If the books is converted to epub, that might not be moved or identified properly. That will probably trigger this issue on a Kobo device.

[RonaldP]

So, I feel like an idiot, but I can't figure out how to use Polish. I see that it's a plugin, but can't find a way to open it. Please advise.

[RonaldP]

Originally Posted by davidfor

That is what I expected. The cover and the first page of the book are separate things. I tend to assume the first of an ebook is the cover, but, some publishers do not. They might include the cover image in the book, but, don't link it to a page. And some will use a nice cover in the store, but, put a simpler cover inside the book and on the first page. Penguin is a publisher that tends to do these.

Another issue is that, for various reasons, books on Kindles can have the cover as the last page. If the books is converted to epub, that might not be moved or identified properly. That will probably trigger this issue on a Kobo device.

The book is an original epub, not converted from Kindle. And note that I used Calibre to download and add a cover, to no effect. I presume, perhaps incorrectly, that Calibre would position the cover where it can be read by the e-reader.

[hobnail]

Originally Posted by RonaldP

I will try these things, but I am quite mystified why it would be a problem for this specific book and not for any others from the same sources.

I agree, but I'm tired of being mystified so I just use the Polish Books plugin. If you don't see its button go to Preferences and click on Toolbars & Menus. There are potentially other useful buttons on the left that you might copy to the right. I had books from Project Gutenberg where something was haywire about their cover and it caused the margins in the chapters of the book to be negative with text off of the left side of the screen.

[davidfor]

Originally Posted by RonaldP

So, I feel like an idiot, but I can't figure out how to use Polish. I see that it's a plugin, but can't find a way to open it. Please advise.

Polish books is a built-in plugin. You will need to put it on a toolbar or menu. Open the preferences, go to the toolbar page and select the toolbar or menu you want to put the button on. Then find it in the left-hand list, select it and press the arrow in the middle to add it to the right-hand list. When you save the options, the button will be on the menu or toolbar you chose.

Now, select the book and press the button or choose the menu item. A dialog should show with various items you can do. Select the "Update cover in book" file option and any others you want to do, then press the OK button. That will start a job to update the cover.

Also, I probably should have mentioned that when you change the metadata or cover in the library, calibre updates its database, but does not update the actual book. It only updates the book when you do something like send the book to a device, edit it, do a conversion or one of several other actions. The cover can be updated at these times, but, calibre needs to be able to find the cover in the book. If the cover isn't marked correctly, this won't happen.

[RonaldP]

It would be quite funny if it weren't so frustrating. I opened Polish, and it had the simple option to fix the cover. So I did. Deleted the existing book from the reader, added the book again from Caliber. No joy, no cover. Did it again. Again no joy. I tried using Polish with and without the e-reader attached. No difference.

The Polish log said it had replaced the cover.

The cover now shows up in the viewer within Caliber (progress!) but not in the e-reader. This suggests that the "new" version of the book is not actually getting to the Kobo.

[RonaldP]

Wait! There's a new wrinkle!

The cover now shows up as the first page of the book, which is really not a benefit. I'll never look at the first page of the book again after I start reading.

What it doesn't do is show up on the "Sleeping" display (so I know what book is waiting for me to read), and it doesn't show up as a thumbnail in the Home screen of the Kobo, just a blank space with nothing.

[RonaldP]

But . . .

A full shutdown of the Kobo and a restart fixed it all. Thanks to you all for your help.

R.

[davidfor]

You hit a caching issue. Replacing the book like that isn't really something that Kobo supports. In fact, if you update a book manually, the device will remove all the information it knows about the book and then add it as a new book. Which means you lose the reading status, collections and any annotations. The KoboTouch driver in calibre cheats and tries to make the device not think that the book has been replaced. But, it means that the device does not know to generate a new cover. It will happen eventually such as after several other books have been opened. But, restarting the device is the quickest way.

I have mentioned this to Kobo, but I'm not surprised it hasn't been fixed as it only happens because of the cheat.

[RonaldP]

My biggest confusion was (and remains) that I added the same file to my wife's Kobo, at the same time as I did to mine, and the cover displayed perfectly.

Anyway, thanks again to all of you.

R.