KF8, ASIN and Covers

[odamizu]

Originally Posted by Katsunami

... The only reason I can think of why they do it like that is because it could be impossible for the Kindle to extract the cover. For example, all of my covers are 1024x768 pixels, where possible ... If the AZW/dual-mobi format is compressed, like EPUB, the Kindle would need to uncompress it, copy the cover out of it, remove the decompressed book, and then shrink the cover. For large books, that may take quite some effort, not to mention time.

Every EPUB reader I know extracts covers from the ebook and shrinks it to create thumbnails for cover view. All my Sonys do this, iOS epub reader apps (Marvin, Bluefire Reader, Stanza) do this.

Only Amazon relies on an external server to download cover thumbnails. Why? I can't imagine it's because they can't figure out how to extract the cover from the ebook and shrink it the way epub readers do. I was actually shocked and befuddled when I got my first Kindle and discovered this was the Amazon way.

Originally Posted by magarto

... If the ASIN is incorrect (because I have too many books without ISBN) I use the python script.

Btw, ASIN and ISBN aren't the same. ASIN is Amazon's internal identifier, ISBN is a standardized identifier used by all booksellers, publishers, libraries, etc.

In any case, if you have a lot of books, looking up the ASIN for each and every one would be a major pain in the you-know-what, and while the Calibre metadata download option can help automate the process, I find it doesn't always work.

Glad you found a method that works for you!

[eschwartz]

Originally Posted by odamizu

Yup. The book has to be available on Amazon.

Incidentally, you can insert any ASIN you like, it doesn't have to match the title. The Kindle will pull whatever cover matches the ASIN, even if it's a totally different book

If a book has multiple editions, each with their own ASIN, you can switch covers by switching ASINs. Goodreads is a good source for ASINs for editions that are no longer available for sale and therefore no longer searchable on Amazon's site. Visiting different Amazon sites by country will also give you different ASINs, allowing you to pick between, say, UK, Canada, and US covers, if they're different.

But still, as you say, it's silly -- nay, RIDICULOUS! -- that Amazon pulls thumbnails from their server rather than simply extracting them from the ebook. Seems like a whole lot of extra, unnecessary effort for everyone, including them.

I know you can do all that, but honestly it is just sooooooo much easier to sideload with calibre. Or at least just use quiris' script. It may be worth bundling as a KUAL extension, actually.

Originally Posted by Katsunami

(First, I'd like to say that I never use the Amazon e-mail service, so I don't know much about it.)

The only reason I can think of why they do it like that is because it could be impossible for the Kindle to extract the cover. For example, all of my covers are 1024x768 pixels, where possible. Most of them are around 500 kB. Many of my books are in the fantasy-genre, and have large maps.

If the AZW/dual-mobi format is compressed, like EPUB, the Kindle would need to uncompress it, copy the cover out of it, remove the decompressed book, and then shrink the cover. For large books, that may take quite some effort, not to mention time.

Downloading a 50-100 kB or so thumbnail would be MUCH faster.

The book has to be extracted for reading, one assumes... anyway, the cover can be extracted and shrunk... which is what the Kindle already does, if the book has a cdetype="PDOC"! And as observed, the Kindle is somewhat unique in doing this.

One would hope at least, if speed was their motivating factor, that it would first check for a downloadable copy and then fall back on extraction. This would be much faster for books that did come from Amazon but were downloaded and added to the Kindle via USB... which also suffer this problem.
Extraction is way way WAY quicker than waiting an indeterminate time for an internet connection to be activated.

[odamizu]

Originally Posted by eschwartz

... it is just sooooooo much easier to sideload with calibre ...

Only if you use Calibre to manage your library, which I don't

[Little.Egret]

Originally Posted by odamizu

[...]

But still, as you say, it's silly -- nay, RIDICULOUS! -- that Amazon pulls thumbnails from their server rather than simply extracting them from the ebook. Seems like a whole lot of extra, unnecessary effort for everyone, including them.

If the thumbnail is for a book which isn't on device but only in the cloud they have to use a different method, so the chap in charge of coolness decided to standardise so it was always done the same way.

[odamizu]

Originally Posted by Little.Egret

If the thumbnail is for a book which isn't on device but only in the cloud they have to use a different method, so the chap in charge of coolness decided to standardise so it was always done the same way.

Ah. Okay, I'll buy that.

Though doesn't Nook show covers for cloud books (or "archived" books in Nook lingo) while still pulling covers for on-device books from within the ebook? It's been a while since I played with a Nook, so my memory could be faulty.

[eschwartz]

It would be perfectly reasonable to use extraction as a fallback option -- like I said already, it would certainly be a lot faster if the Amazon-sourced book was downloaded from a computer and sideloaded.

[Katsunami]

Originally Posted by eschwartz

The book has to be extracted for reading, one assumes...

I don't know. I have a lot of Delphi Classics, some of which are 25.000+ pages, such as the Anthony Trollope one (using my own setting of 2400 characters per page). When opening them using the calibre viewer, it takes a LONG time, and this is a desktop computer. I assume calibre is extracting the book and completely loading it into memory. (I'm opening the EPUB version, by the way.)

The Kindle opens the converted AZW3 version instantaneously, so it is not extracting the entire book. Maybe it's possible to extract only the OPF/NCX files, and then only extract the files one by one during reading. Or something...

[eschwartz]

Yep, and same goes for just extracting the cover resources.

(calibre, a piece of desktop software, presumably assumes people have the necessary RAM and CPU to preload everything.)

[odamizu]

I can understand (sort of) wanting to standardize how covers are handled, i.e., downloading from server so that covers from books on device and covers from books in cloud are handled the same. But I don't buy that it's too much effort or time-consuming for a Kindle to extract a cover from within the ebook file.

On my Sonys, when you add a book, it takes maybe 2 seconds for the reader to extract the cover and create a thumbnail, which is then stored in a separate thumbnail folder. This happens only once, the first time the book is added.

[tomsem]

I have a couple of Personal Document books that do show cover thumbnails on my PW1. I have never bothered to try to figure out why, as I don't use Cover view on that device. calibre never touched them. I think there may be a 'magic' cover resolution that will get thumbnail image generated, at least that used to be the case on Fire.

Thumbnails show for all of the books on my Fire HD6 (and ios, android) once they're downloaded (except Fire only shows them in Collections, Carousel, and task switcher, not in Docs view).

[eschwartz]

Persona Documents (has Personal banner and might appear under Docs filter) always have covers extracted on E-Ink. Dunno how the Fires may differ, but this much at least is likely to be the same.

[shalym]

Originally Posted by eschwartz

Persona Documents (has Personal banner and might appear under Docs filter) always have covers extracted on E-Ink. Dunno how the Fires may differ, but this much at least is likely to be the same.

...except when they don't. I have quite a few "Personal Docs" on my Kindle that don't have covers when looked at in cover view. I checked, and while some of those don't have covers embedded in the book, some of them do. I have no idea what causes some to show covers while others don't, and to tell the truth, I don't care, since I don't usually use cover view. I'm just putting it out there as a bit of data to add to the confusion

Shari

[AcidWeb]

AFAIK personal documents don't use cover declared in EPUB but a special thumbnail (very small one) made during MOBI conversion.

[shalym]

Originally Posted by AcidWeb

AFAIK personal documents don't use cover declared in EPUB but a special thumbnail (very small one) made during MOBI conversion.

This still doesn't explain why some of my personal docs have covers and some don't. Every single one of them came from Amazon's cloud. If I have time this weekend, maybe I'll do some experiments. Maybe the ones with covers were emailed, and the ones without used the send to kindle app? I just don't know.

Shari

[fendesa]

depends on a set of conversion, if you use calibre program, in the edit conversion, remove the flag on a shared document, and your personal documents will appear with a large cover, without written personal document.
summary: open calibre, edit metadata, remove the check mark for share, converted to mobi or azw3, and you will appear as if it were an original book by amazon.