Calibre Resizing Inserted Cover Size

[please55]

Let's say I strip out a book's cover using Modify Epub.

Download a new one - 1124,1800 (cover.jpg).

Then use the same Modify Epub to insert the new cover.

When I look at the html, I see that the referenced cover has been resized, 469,751 (cover.jpeg) and now uses .jpeg

Any particular reason for this behavior? The full size cover, while not used, can still be found in the images list (viewed through included editor).

My Tweaks preference if it matters is still default -
maximum_cover_size = (1650, 2200)

[theducks]

What WAS your device profile? You want Tablet for new stuff. That does not resize images.
But remember, any previous books that had conversions will use the profile settings from THAT TIME, unless reset (that will pull the current Default the next time that book is used).
Bulk mode Metadata edit: tick the box Remove Stored Conversion settings for selected books. There is also a clear box/tick on the conversion dialog.

[please55]

Hmm, when I set up calibre I usually go with the default settings - generic e-ink i believe.

I've tried deleting the conversion settings in Bulk Mode then reapplied the cover but sizing still happens.

How would I go about changing the current profile settings? I'm not sure where in the preferences that would be.

[theducks]

Preferences: common options: Page setup (the side bar)
or run the Welcome wizard on the preferences icon (right click) menu

This does not change previous usage.

You need to follow my instructions previously, this will reread the DEFAULT conversion for later conversions.
Once all settings have been made (and old ones cleared): Embed Metadata may update the internals << not tested: never needed large covers

[please55]

Thanks that seems to have taken care of the resizing issue. However, Modify Epub / Polish, both insert a new cover image into the file structure - cover.jpeg

So to recap. I can delete the cover with Modify Epub, cover.jpg is still part of the epub file structure but is no longer displayed when the epub is opened.

If I then change Modify Epub to insert the cover, it works as intended but now cover.jpeg is now part of the epub file and what you see when epub is opened.

So although both files are now the same dimensions (after device preference change) why not just use cover.jpg that's already in the epub?

Not a huge deal but why duplicate?

[theducks]

Originally Posted by please55

Thanks that seems to have taken care of the resizing issue. However, Modify Epub / Polish, both insert a new cover image into the file structure - cover.jpeg

So to recap. I can delete the cover with Modify Epub, cover.jpg is still part of the epub file structure but is no longer displayed when the epub is opened.

If I then change Modify Epub to insert the cover, it works as intended but now cover.jpeg is now part of the epub file and what you see when epub is opened.

So although both files are now the same dimensions (after device preference change) why not just use cover.jpg that's already in the epub?

Not a huge deal but why duplicate?

Not a "duplicate".
cover.jpeg is Calibres uniform name

The other is just a image that looks like the cover or it would have been replaced.

Cover is 2 distinct declarations in a EPUB file
1) the Image
2) the file that uses it. In Calibres inserted version, this is Jacket and will replace any previous file marked in the OPF as cover. (the name does NOT make it so.
Calibres editor can insert a page as a Cover (the declarations are taken care of)

[please55]

Thanks for you time and trying to explain the concepts to me

Last point escapes me at the moment but I can strike out from here. Cheers.

[theducks]

Last point is (probably what you had):
You create a page. You add a picture (and maybe some text).
That is NOT a cover unless you make the declarations (semantics) that set both pieces to COVER

[please55]

Ahhh, thank you. Played around some more. Getting it finally.

Basically if its not declared in the manifest then calibre can't 'know' its there. It's not checking the image list for 'cover.xxx'; just the manifest directly.

Now just for tinkering purposes. I had calibre set up a cover page for a book. Then went in the editor, imported the same image as cover.jpg and simply changed all the references in the manifest/html from cover.jpeg to cover.jpg. (I also experimented with png separately.)

Then I clicked on Modify Epub again to do its thing. It seems that the command doesn't 'check' the epub. It appears to take the image set in the database and insert it into the epub file as a .jpeg regardless of what's there.

--

So one might want to be prudent about using 'Modify Epub' to update cover images if you're a stickler for that kind of stuff. It appears even if an epub does declare an image as a cover and has a corresponding html page for it - 'Modify Epub' is 'destructive' in the sense its not checking, it will overwrite it with its own version. Which 99% of people won't care about and I wish my mind would just let it go. But now that I get how it works, I do have the painstaking option of manually updating the manifest and importing the correct high rez files.