Content How to download full resolution images?

[ATimson]

For books with interior illustrations, I've noticed that the downloaded file size from Amazon's site is significantly smaller than their claimed file size on the website.

Comparing two books in the same series from the same publisher, one purchased from Amazon and one from B&N, Amazon appears to be downscaling the images before delivery. (I know this isn't a "true" 1:1 comparison but it's the best I can get without buying a second copy of a book!) Comparing the same volumes between sites, both say they're roughly the same size. But when I actually download the Kindle book from the website, the file size is about 10% of the promised one, and the images inside are of lower resolution than the images from Nook books.

(Using the copyright page to be as like-for-like as possible: the Kindle version has under half the total number of pixels, and the file size is 15% that of the Nook version. So it sounds like there's some image quality shenanigans going on after the resizing too.)

Sure, it looks fine on my Kindle, but for archival purposes I'd like the whole thing. Is there any way to download the full-fat Kindle book?

[jhowell]

Amazon will deliver the same book in different formats with different image resolutions based on the needs of different devices. Generally books delivered to e-ink Kindle devices are the most downsized. Images in books delivered using Kindle for PC tend to have higher resolution.

The thread Some questions regarding Oasis 2 & comics/manga contains comparisons of file sizes for image-heavy books under different conditions.

[ATimson]

Hmm. That thread said people were able to get better files with Kindle for PC, but both v1.17 and v1.24 end up giving me the same files as I got on my Paperwhite.

This is turning out to be more of a pain than I thought!

[jhowell]

It would help if you could be specific about which book you are using for your investigation and the actual file sizes you are seeing.

[ATimson]

I haven't tried with any free ones, just paid ones. Let me try and do some experimentation with free ones and/or samples and get back to you.

[ATimson]

Okay. I tried all three books linked in the first post of the other thread you linked to. I get just the AZW3 files in Kindle for PC 1.24; I don't get the AZW6 files that you were getting when you tried them...

Is there another version you'd suggest using?

https://www.amazon.com/Valiant-X-Man.../dp/B072JXR28J
Expected size: ~33 MB
Actual size (Kindle for PC 1.24 and downloaded to transfer via USB to Paperwhite): 5.70 MB

https://www.amazon.com/FCBD-2017-All.../dp/B06XB1LXMC
Expected size: ~29 MB
Actual size: 5.47 MB

https://www.amazon.com/Naruto-Retros.../dp/B015WZJDO6
Expected size: ~92 MB
Actual size: 31.5 MB

[jhowell]

Originally Posted by ATimson

https://www.amazon.com/Valiant-X-Man.../dp/B072JXR28J
Expected size: ~33 MB
Actual size (Kindle for PC 1.24 and downloaded to transfer via USB to Paperwhite): 5.70 MB

I used the latest version of Kindle for PC to download that book just now and this is what I see in the My Kindle Content\B072JXR28J_EBOK folder.

01/01/2019 06:32 PM 5,980,908 B072JXR28J_EBOK.azw
01/01/2019 06:32 PM 28,258,896 CR!1G3BK8ZB6H1BKAJBG87FZXBT1TY2.azw.res

Newer versions of Kindle for PC use the extension .azw for the main file (azw3 in this case) and .azw.res for auxiliary resources (azw6 in this case).

See this post from the linked thread for information on obtaining the high res images contained in the azw6 file.

[ATimson]

With v1.24, I get the .azw files but no corresponding .azw.res files for that book (and the two others).

You say you're using the latest (which I believe is v1.27?). I thought you couldn't suppress KFX downloads for v1.25 and above (per here). Is it just luck that you're getting AZW3/6 with the newest version, or is there a way to suppress KFX on newer versions that's not documented in that thread?

[jhowell]

Originally Posted by ATimson

You say you're using the latest (which I believe is v1.27?). I thought you couldn't suppress KFX downloads for v1.25 and above (per here). Is it just luck that you're getting AZW3/6 with the newest version, or is there a way to suppress KFX on newer versions that's not documented in that thread?

I used version 1.25.1 (52064). It does download most books in KFX format (with new DRM), but not all. Comics are one of the exceptions. They always download in azw3 format.

When I did my original examination last March I had an older version installed, probably 1.21.0 (48017).

I suspect that the hack that disables KFX also disables download of high res images. Try undoing that and downloading the book again.

Added: It might be easiest to just use a version of K4PC that predates KFX.

[ATimson]

Aha, good thought. Reenabling KFX, I get the .azw.res file for comics, but that of course means prose books with illustrations I get KFXes.

Unfortunately, it looks like versions predating KFX (v1.17) don't support higher-resolution files at all.

So leaving KFX enabled, I can at least get full-resolution comics downloaded; but I'd have to get KFX decryption working to get full resolution prose books.

Hmm. Have some thinking to do before buying more light novels. Thanks for your help!

[shalym]

Originally Posted by ATimson

Aha, good thought. Reenabling KFX, I get the .azw.res file for comics, but that of course means prose books with illustrations I get KFXes.

Unfortunately, it looks like versions predating KFX (v1.17) don't support higher-resolution files at all.

So leaving KFX enabled, I can at least get full-resolution comics downloaded; but I'd have to get KFX decryption working to get full resolution prose books.

Hmm. Have some thinking to do before buying more light novels. Thanks for your help!

Or, since you also own a Paperwhite, you can use the download for USB option from your amazon content and device page. That will always give a kf8 file rather than kfx.

Shari

[ATimson]

Originally Posted by shalym

Or, since you also own a Paperwhite, you can use the download for USB option from your amazon content and device page. That will always give a kf8 file rather than kfx.

That gives me a KF8 file, but with reduced-quality images. Fine for reading, but I'd like to have full-fat images for archival purposes (and for use on future devices with better screens).

[j.p.s]

Originally Posted by ATimson

That gives me a KF8 file, but with reduced-quality images. Fine for reading, but I'd like to have full-fat images for archival purposes (and for use on future devices with better screens).

1a. D/L KFX via K4PC (I think the images can be extracted from the azw6 without cracking the KFX.

1b. D/L KF8 (AZW3) with transfer over USB option (then Alf)

2. kindleunpack the azw3 to get EPUB.

3. Substitute high res images into EPUB. You now have your archival book.

4. (Optional) Use kindlegen (or calibre) to make hi-res azw3 from the epub. Be sure to check whether kindlegen or calibre reduced resolution.

[jhowell]

Originally Posted by j.p.s

1a. D/L KFX via K4PC (I think the images can be extracted from the azw6 without cracking the KFX.
...

In KFX format books the .azw.res files are actually in azw9 format. Techniques that work on azw6 will not be helpful with those.

Instead you could de-DRM the KFX book and then either:

• convert to EPUB using the KFX Input plugin in calibre (making sure to select "tablet" output profile to avoid image resolution changes) and extract the images from that or
  
• unpack the de-DRMed KFX into a ZIP file using the command line interface of the KFX Input plugin and extract the images from that.

In either case putting things back together with the azw3 will be a lot of work.

[j.p.s]

Thanks. I guess that by the time there are tools for azw9 they will switch to something else.

But if the KFX Input plugin makes an EPUB with high resolution images, why isn't it trivial to convert that to azw3?