Custom covers with ebook-convert?

[julo]

I have a .cmd (batch) file (courtesy of this blog) which I am developing further.

When making epub files in batch mode with that script one of the items I try to do is add a cover if one exists by the same name in the same folder. I have it working, more or less, except if there is a file without matching cover image.
In that case my script uses the default cover (actually does not specify anything). What happens however is that I get each time a different cover from the Calibre > Edit Metadata > Change cover > Generate cover library.

However what I really was looking for is a custom cover with the metadata. For that I installed the Generate Cover plugin and tried different settings but could not get what I wanted. I then deleted the plugin trying to get back to the original Calibre settings. My next step was going to be to replace image library.png in C:\...\Calibre\Calibre\resources\images (and/or lt.png and/or calibre.png) in the hope that would give me a custom image. However I do not get the Calibre standard cover image (the one showing books) any more with ebook-convert.exe. Restore default has no effect.

I run Calibre in portable mode and even downloaded a new version (2.17.0) which I extracted into a new separate folder and ... still covers from the library. (Does Calibre write to the registry, even if portable? Should I clear that? How?)

Two questions:
1) How can I get back to Calibre's original settings, at least in regard to default cover.
2) Is there a way to have custom images, inclusive of metadata, used for cover images when making epubs with ebook-convert.exe. Might changing library.png work? (Keep in mind I do not want to edit epub covers individually nor in batches but get a custom cover when I run ebook-convert.exe. in batch mode.)

Any help/hints would be greatly appreciated.

[BetterRed]

Originally Posted by julo

What happens however is that I get each time a different cover from the Calibre > Edit Metadata > Change cover > Generate cover library.

If you right click the Generate cover button in single metadata edit and you will find a set of customisation facilities, where you can prevent the cycling.

AFAIK the Generate Cover feature in Metadata edit and the Generate cover PI are entirely separate, I use both without any 'interference' between them.

Calibre itself does not use the registry in any of its guises. The only registry entries that refer to the installed versions of Calibre are put there by the Windows installer program msiexec.exe; they are used by the installer itself and the Control Panel Programs and Features applet, which will remove them when the program is uninstalled. Not even that is done for the portable version.

BR

[theducks]

BR
Generate cover gained a random feature somewhere along the (recent) line (I can't find the what's new to link it)

In metadata edit window there is now an now on the button. Right click to customize

BTW repeated clicking the button steps thru a number of different versions

[julo]

Originally Posted by BetterRed

If you right click the Generate cover button in single metadata edit and you will find a set of customisation facilities, where you can prevent the cycling.

Even though I got new glasses last week I still cannot find anything which resembles anything at what you hinted. The closest would be IMHO Restore Defaults but that does not do anything (well not quite true, it puts it to Earth-Banner) but does not restore the six books cover as I mentioned.
Can you be more specific what exactly to click where?

[BetterRed]

Originally Posted by julo

Even though I got new glasses last week I still cannot find anything which resembles anything at what you hinted. The closest would be IMHO Restore Defaults but that does not do anything (well not quite true, it puts it to Earth-Banner) but does not restore the six books cover as I mentioned.
Can you be more specific what exactly to click where?

@julo - if you only tick one colour and one style then all your covers will look the same. That's what the instructions say - after you apply deductive reasoning thereto

Took me a while to even find the right click worked. I would like to associate metadata with colours and style - eg blue if economics, brown if law, blocks if government, banner if academia etc.

The generated cover is the cover.jpg in the book folder (press 'o'). It wont change unless you regenerate it - btw same goes for Generate Cover PI.

I can see how the word 'Generate' could be taken to mean create as needed, but that's not the way it works. IMO 'Make' would be a better word - only one syllable and less ambiguous - but brevity and clarity are in short supply in the 21st century

BR

[julo]

I do not think we are talking the same language. When I run "ebook-convert" I do not even have Calibre open.

I will do further investigation by stripping everything unessential off, maybe something will show up. I had hoped to get some pointers where possibly to look.

[theducks]

Originally Posted by julo

I do not think we are talking the same language. When I run "ebook-convert" I do not even have Calibre open.

I will do further investigation by stripping everything unessential off, maybe something will show up. I had hoped to get some pointers where possibly to look.

Many CLI tools use settings that were previously made in the GUI

Some CLI tools have specific override switches.
these 3 affect EPUB out

--no-default-epub-cover

    Normally, if the input file has no cover and you don’t specify one, a default cover is generated with the title, authors, etc. This option disables the generation of this cover.

--no-svg-cover

    Do not use SVG for the book cover. Use this option if your EPUB is going to be used on a device that does not support SVG, like the iPhone or the JetBook Lite. Without this option, such devices will display the cover as a blank page.

--preserve-cover-aspect-ratio

    When using an SVG cover, this option will cause the cover to scale to cover the available screen area, but still preserve its aspect ratio (ratio of width to height). That means there may be white borders at the sides or top and bottom of the image, but the image will never be distorted. Without this option the image may be slightly distorted, but there will be no borders.

[BetterRed]

@julo - I think we're all confused - cover generation is a function of editing the metadata, not conversion - I wasn't aware it came into play with conversion.

I tend to worry about covers after doing any conversion. Since I did my initial upload to calibre, I've not used the cli programs very much, which was well before the new generate cover facility was implemented in metadata edit..

Does your batch file include ===>>> ebook-meta. If you set the cover generation settings as you want them in the Edit Metadata GUI (e.g. one colour, one style, and check the Save as default option (bottom left), maybe it will honoured by the ebook-meta program. If it doesn't then maybe ebook-meta needs another option "generate-cover'. You can make a formal request here ==>> Bugs : calibre

BTW 1: I noticed the blog page you posted suggests putting the batch files in the calibre directory. That is not a practice I would recommend, if you ever needed to do a clean reinstall of calibre (and it does happen from time to time) then you'd lose your scripts.

BTW 2: I don't think you can run the Generate Cover PI from the command line.

BR

[julo]

I think finally we are getting somewhere, at least we are not talking past each other.

@duck:
I am aware of the override switches and used '--no-default-epub-cover' first. But I like to see the title, at least, on the cover page so am trying to still use a cover, but not the Calibre (6 books) default cover.
I first looked what could be done via the 'Generate cover' PI but did not find any way. Then, or at the same time, I looked at the 'Edit Metadata Generate cover' but did not like that either.
I then tried to backtrack, deleted the 'Generate cover' PI, and then intended to modify the image which Calibre uses for its default cover. First step was to use the (6 book) default cover and go from there. My problem is that I cannot get the default cover any more. My hunch is there is a bug somewhere but I cannot say yet where, if at all.

I did already, what I thought was, a clean install and even there started out with 'Edit Metadata Generate covers'. Obviously I have to be more careful, since apparently it was not clean enough.

@BR:
Ref.: BTW1: Not to have the script in the Calibre folder was my first change to the script. I noticed right away, too, that I lose it with every update, doesn't even have to be clean re-install.
Ref.: BTW2: I had hoped since I got the impression that 'from now on' a certain cover would be used as the default.

Don't know yet about making a formal request.

===================

Anyway my next step is going to be to strip the script to the bare minimum (might even post it) and then start with a guaranteed clean Calibre installs and see what happens.

Since 'Generate cover' PI (too bad they both have the same name) seems to be out of the picture I am not sure this is the right thread any more.

[BetterRed]

Originally Posted by julo

Since 'Generate cover' PI (too bad they both have the same name) seems to be out of the picture I am not sure this is the right thread any more.

Moderator Notice
Done

I would have that clean install include a fresh %appdata%calibre - just backup/rename the existing one, an install will create a vanilla one.

BR

[eschwartz]

Originally Posted by BetterRed

If you set the cover generation settings as you want them in the Edit Metadata GUI (e.g. one colour, one style, and check the Save as default option (bottom left), maybe it will honoured by the ebook-meta program.

@julo,

I don't know about this particular case, but generally you (rhet) will find many aspects of the CLI, where if a feature can be done in Edit Metadata (GUI) as well as through the CLI tools, the default will be to use the library preferences.

IOW, if ebook-convert is told to generate a cover (using the same backend code used in the builtin Generate Covers feature) then your library settings *should* control and limit what kinds of covers are generated through ebook-convert.

When generating covers, a color scheme for the cover is chosen at random from the color schemes below. You can prevent an individual scheme from being selected by unchecking it. The preview on the right shows the currently selected color scheme.

If you do this^^, ebook-convert as well should start only generating covers using that restricted set.

[julo]

Originally Posted by eschwartz

If you do this^^, ebook-convert as well should start only generating covers using that restricted set.

I just did that (v2.14 though). I unchecked all four Colors and Styles since I do not want any but still got one of them. Seems whatever line is highlighted, even though not checked, is used. And one line is always selected.
Restore defaults sets it to the 'Metadata Generate cover' defaults (all checked).

That doesn't make much sense and my original question still is unanswered. "How can I go back to the Calibre default cover" short of re-installing Calibre?

[eschwartz]

The old style covers have been completely and utterly superseded by newer versions of calibre.

If you want the old "calibre-logo-under-title+author" you will have to downgrade to before that update.

[julo]

Originally Posted by eschwartz

The old style covers have been completely and utterly superseded.

OK, thanks, let me update and take it from there.

ETA: Nothing changed that I can see when doing an update. Guess have to try a re-install. Does that make sense?

[BetterRed]

@julo I assume your batch script goes something like:

ebook_convert
if a cover exists 
   ebook_meta add the cover

try adding

else
   see Running from command line in Modify ePub Optional Plugin (← click)
        to remove the cover that the convert put there 
        (set options for Modify in the GUI)

Then you can use a search in the GUI for cover:false, and do whatever with built in Gen Cover, Gen Cover PI, Cover download, or roll your own with your favourite image editor.

BR