Kobo not displaying cover

zeltus · 11-23-2012, 06:01 AM

My Kobo Touch does not always display the cover of the book (when in sleep mode)

I have checked the format of titlepage.xhtml in a non-working one... it is exactly the same as in a working epub book (looks to have been generated by Calibre, FWIW)

The cover displays fine in Sigil and of course in Calibre.

Anyone got any ideas? Kobo themselves haven't offered much by way of help - I want to know the deep, dark, techie secrets of what works and what doesn't and why. Because I like that sort of thing.

Obviously, doesn't stop me reading the book, but it is an irritation.

Thanks

Bill

davidfor · 11-23-2012, 08:05 AM

This sounds like it should be in the Kobo forum rather than the calibre. Or at least in the device sub-forum. Until it is moved, I'll answer it here.

I think you already know that the Touch uses the first page of the book as the cover. It generates several different sized images and saves them for use later. When it generates the images depends on the firmware. Pre 2.0.0 generated four sizes when it first sees the book. All the 2.x.x generates them as needed but stores for later use. Unless the book is on the SD card. In that case, it generates the image each time it needs it.

Apart from this, the firmware has had problems. 2.0.0 had a problem where it used the wrong cover for the sleep cover the first time it went to sleep after opening a book. It would use the cover from the previous book. The next time it went to sleep, it would use the cover for the current book.

There is also a problem related the the number of images stored and the FAT32 file system. There is a maximum number of files that can be in a directory on a FAT32 file system. This is reduced if long file names are used. The Kobo devices will tend to have very long file names for the cover images. The number seems to be between 7000 and 8000 images in the directory. Depending on the firmware version, there are between two and four images per book on the device. So, you could hit the problem with about 2000 books on the device. With more than 2500, you definitely will. If this is the problem, I am not sure if a blank cover is used or the simple text cover (see below). But this will also be used in the library list and home screen.

Sometimes, the cover used will be a simple text cover. This will have the title of the book and the book type under it. This is always used for TXT and RTF files but will also be used for other books at times. If the cover image for a book hasn't been generated when it is displayed somewhere, the text cover will flash up and then be replaced by the books cover. Occasionally, this doesn't happen and the text cover stays.

That's the basics for covers. There is more in posts in the Kobo forum. Especially about margins.

But, what is the actual problem? "does not always display the cover of the book (when in sleep mode)" does not actually tell me much. Is it displaying the wrong cover? The Kobo sleep logo? Or something else. And does the first page display correctly when reading the book on the device? Also, what firmware version and calibre version. The latter is probably not important as I doubt this is a calibre problem, but we should know just to be sure.

zeltus · 11-30-2012, 06:09 AM

Aah thanks for that.

In fact I didn't know what defined the front cover, so this is all new and very useful info. ta.

Kobo version is 1.9.17 - which, now I have noticed that, is I hope about to change - an update has been initiated (at least, I hope it has!)

I think I might well have been hitting the Fat32 limit as I certainly have 1300 or so books on board.

The symptom is, that when I read a book, I see the first page (= cover image) fine. When I sleep, I see a basic, blank, book icon instead.

But if I am hitting the Fat32 limit, there isn't much I can do. It doesn't really matter it is just a minor irritation. But as I have paid* for it, I want to see it! :-)

*some weird psychosales thing going on - if I get something for free, I am grateful for it to work at all. If Ipay for it, doesn't matter what sum, little or great, it better darn well work. Perfectly. All the time. Or else.

davidfor · 11-30-2012, 07:36 AM

Quote:

Originally Posted by zeltus

I think I might well have been hitting the Fat32 limit as I certainly have 1300 or so books on board.

The symptom is, that when I read a book, I see the first page (= cover image) fine. When I sleep, I see a basic, blank, book icon instead.

But if I am hitting the Fat32 limit, there isn't much I can do. It doesn't really matter it is just a minor irritation. But as I have paid* for it, I want to see it! :-)

The new firmware might help. As I said, with the 1.9.17, four cover images were generated for each book when it was first loaded. 2.1.5 will generate up to three but only when they are needed. That should delay when you hit this problem.

Banphrionsa · 08-09-2013, 05:52 PM

Hi!

I just started using Sigil and I have version 7.3. I can see the cover on ADE, Kobo app on my Ipad, and iBooks. But when I use ADE to download the epub onto my actual Kobo, the cover is blank. Image is named cover.jpg. Could it be too large? I designed it at 1600 x 2400.

11-23-2012, 06:01 AM	#1
zeltus Junior Member Posts: 9 Karma: 10 Join Date: Mar 2011 Device: none	Kobo not displaying cover My Kobo Touch does not always display the cover of the book (when in sleep mode) I have checked the format of titlepage.xhtml in a non-working one... it is exactly the same as in a working epub book (looks to have been generated by Calibre, FWIW) The cover displays fine in Sigil and of course in Calibre. Anyone got any ideas? Kobo themselves haven't offered much by way of help - I want to know the deep, dark, techie secrets of what works and what doesn't and why. Because I like that sort of thing. Obviously, doesn't stop me reading the book, but it is an irritation. Thanks Bill

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11-23-2012, 08:05 AM	#2
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	This sounds like it should be in the Kobo forum rather than the calibre. Or at least in the device sub-forum. Until it is moved, I'll answer it here. I think you already know that the Touch uses the first page of the book as the cover. It generates several different sized images and saves them for use later. When it generates the images depends on the firmware. Pre 2.0.0 generated four sizes when it first sees the book. All the 2.x.x generates them as needed but stores for later use. Unless the book is on the SD card. In that case, it generates the image each time it needs it. Apart from this, the firmware has had problems. 2.0.0 had a problem where it used the wrong cover for the sleep cover the first time it went to sleep after opening a book. It would use the cover from the previous book. The next time it went to sleep, it would use the cover for the current book. There is also a problem related the the number of images stored and the FAT32 file system. There is a maximum number of files that can be in a directory on a FAT32 file system. This is reduced if long file names are used. The Kobo devices will tend to have very long file names for the cover images. The number seems to be between 7000 and 8000 images in the directory. Depending on the firmware version, there are between two and four images per book on the device. So, you could hit the problem with about 2000 books on the device. With more than 2500, you definitely will. If this is the problem, I am not sure if a blank cover is used or the simple text cover (see below). But this will also be used in the library list and home screen. Sometimes, the cover used will be a simple text cover. This will have the title of the book and the book type under it. This is always used for TXT and RTF files but will also be used for other books at times. If the cover image for a book hasn't been generated when it is displayed somewhere, the text cover will flash up and then be replaced by the books cover. Occasionally, this doesn't happen and the text cover stays. That's the basics for covers. There is more in posts in the Kobo forum. Especially about margins. But, what is the actual problem? "does not always display the cover of the book (when in sleep mode)" does not actually tell me much. Is it displaying the wrong cover? The Kobo sleep logo? Or something else. And does the first page display correctly when reading the book on the device? Also, what firmware version and calibre version. The latter is probably not important as I doubt this is a calibre problem, but we should know just to be sure.

11-30-2012, 06:09 AM	#3
zeltus Junior Member Posts: 9 Karma: 10 Join Date: Mar 2011 Device: none	Aah thanks for that. In fact I didn't know what defined the front cover, so this is all new and very useful info. ta. Kobo version is 1.9.17 - which, now I have noticed that, is I hope about to change - an update has been initiated (at least, I hope it has!) I think I might well have been hitting the Fat32 limit as I certainly have 1300 or so books on board. The symptom is, that when I read a book, I see the first page (= cover image) fine. When I sleep, I see a basic, blank, book icon instead. But if I am hitting the Fat32 limit, there isn't much I can do. It doesn't really matter it is just a minor irritation. But as I have paid* for it, I want to see it! :-) *some weird psychosales thing going on - if I get something for free, I am grateful for it to work at all. If Ipay for it, doesn't matter what sum, little or great, it better darn well work. Perfectly. All the time. Or else.

08-09-2013, 05:52 PM	#5
Banphrionsa Junior Member Posts: 1 Karma: 10 Join Date: Aug 2013 Device: Kobo	Hi! I just started using Sigil and I have version 7.3. I can see the cover on ADE, Kobo app on my Ipad, and iBooks. But when I use ADE to download the epub onto my actual Kobo, the cover is blank. Image is named cover.jpg. Could it be too large? I designed it at 1600 x 2400.