All the images in my book are now extension .unknown

Tithemi · 06-11-2020, 06:41 PM

Hi, everyone!

I just imported an azw3 book from my 2012 Kindle Paperwhite into Calibre 4.18, and noticed that images weren't loading. The cover .jpeg was fine, but all images in the book itself were there but broken.

Opening the book in edit mode, all those images have the file extension .unknown, which I *assume* is the problem! The editing interface doesn't even list them as images, understandably: it calls them miscellaneous files.

Is this a known issue? How did I manage do it, and is there a way to restore the images?

Many thanks in advance for any help.

BetterRed · 06-11-2020, 07:34 PM

Maybe they are typed as one thing (e.g. 'jpg'), but are in fact something else (e.g. 'png') - and the editor image handler made them 'unknown'.

I've not seen that in ebooks, but I have often seen it in web pages.

BR

jhowell · 06-11-2020, 07:49 PM

Sometimes Kindle books in KF8 (azw3) format have placeholders for images with the actual images contained in a separate azw6 container file. As far as I know calibre does not handle that case.

If that is what is happening here you can use the "Download & transfer via USB" function of the Amazon website to download a copy of the book with images in place.

Tithemi · 06-11-2020, 08:00 PM

Thank you very much, jhowell - that was it!

I really should have noticed that the .unknown files were all FOUR BYTES....

06-11-2020, 06:41 PM	#1
Tithemi Junior Member Posts: 3 Karma: 10 Join Date: Jun 2020 Location: London, UK Device: Kindle Paperwhite	All the images in my book are now extension .unknown Hi, everyone! I just imported an azw3 book from my 2012 Kindle Paperwhite into Calibre 4.18, and noticed that images weren't loading. The cover .jpeg was fine, but all images in the book itself were there but broken. Opening the book in edit mode, all those images have the file extension .unknown, which I assume is the problem! The editing interface doesn't even list them as images, understandably: it calls them miscellaneous files. Is this a known issue? How did I manage do it, and is there a way to restore the images? Many thanks in advance for any help.

06-11-2020, 07:49 PM	#3
jhowell Grand Sorcerer Posts: 7,031 Karma: 91577715 Join Date: Nov 2011 Location: Charlottesville, VA Device: Kindles	Sometimes Kindle books in KF8 (azw3) format have placeholders for images with the actual images contained in a separate azw6 container file. As far as I know calibre does not handle that case. If that is what is happening here you can use the "Download & transfer via USB" function of the Amazon website to download a copy of the book with images in place. Last edited by jhowell; 06-11-2020 at 07:56 PM.

06-11-2020, 08:00 PM	#4
Tithemi Junior Member Posts: 3 Karma: 10 Join Date: Jun 2020 Location: London, UK Device: Kindle Paperwhite	Solved! Thank you very much, jhowell - that was it! I really should have noticed that the .unknown files were all FOUR BYTES....

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
kual extension to open a book	shoelesshunter	Kindle Developer's Corner	14	08-16-2016 12:30 PM
Changed AZW4 book extension to mobi and lost my book cover	BasicGreatGuy	Kindle Formats	0	05-10-2015 09:24 PM
can't read .acsm extension book	jrice4155	PocketBook	1	06-22-2012 02:52 PM
Topaz with azw extension show as Unknown	FF2	Calibre	2	12-14-2010 10:47 PM
Documents with unknown extension	SkyDream	Calibre	2	07-27-2010 02:42 PM

06-11-2020, 07:34 PM	#2
BetterRed null operator (he/him) Posts: 21,628 Karma: 29710338 Join Date: Mar 2012 Location: Sydney Australia Device: none	Maybe they are typed as one thing (e.g. 'jpg'), but are in fact something else (e.g. 'png') - and the editor image handler made them 'unknown'. I've not seen that in ebooks, but I have often seen it in web pages. BR

Advert