Running the cover generator standalone on linux

[olin-shivers]

I'd like to make book-cover images using calibre's cover generator. I *don't* want to do it from the GUI, however. Is there some way I can run the cover generator as a separate program in linux, feeding it author/title/series metadata as command-line arguments, along with the name of the image file for it to produce?

The cover generator's current status as a plugin works fine for doing in-calibre conversions from the GUI. But won't work if one is simply trying to produce a book using other production techniques, outside of calibre, with a GUI-free workflow.

I'm not committed to the calibre cover generator, for that matter. It makes fine covers, but if there's a non-calibre way to make cover jpegs, I'd also be interested in that.

Thanks!

Olin

[kovidgoyal]

Simply convert to EPUB without any cover in the input document and ebook-convert will generate a cover automatically.

[olin-shivers]

Originally Posted by kovidgoyal

Simply convert to EPUB without any cover in the input document and ebook-convert will generate a cover automatically.

Hi, Kovid. Thanks for your instantaneous reply!

What you suggest will produce an *epub* file. Which will unzip into a directory containing a file images/calibre_cover.jpg. I'm just looking for a program that will produce that calibre_cover.jpg file directly, and nothing else. Clearly that is happening at some point in the execution of ebook-convert.

Is there some way to do this? (As a workaround, I *could* use ebook-convert to do an epub->epub conversion on a trivial book, then extract images/calibre_cover.jpg from the result. But that seems like a bit of a hack.)

(I see mention of SVG format covers in the manual, but what ebook-convert makes for me is a jpg.)

Secondarily, it would be nice if there was some way to choose among the various styles (banner, cross, blocks, etc.) of cover image that ebook-convert knows how to produce, and select the color.

Olin

P.S. While I'm writing: are there any plans to have calibre support the current epub standard, 3.1? E.g., a way to have ebook-convert produce books in this format?

[kovidgoyal]

I dont see what's so hacky about it. But if you really want to run just the cover generator, do it like this.

calibre-debug -c "from calibre.ebooks.covers import *; open('cover.jpg', 'wb').write(create_cover('my title', ['my author'])))"

And you can set whatever preferences you like when using the create_cover function, see the sourcecode for details.

As for EPUB 3 sure someday, but since the EPUB standards are a bad joke and there is nothing you can do in EPUB 3 that you cant do in EPUB 2 I'm not particularly motivated to do so.

[olin-shivers]

Originally Posted by kovidgoyal

I dont see what's so hacky about it. But if you really want to run just the cover generator, do it like this.

calibre-debug -c "from calibre.ebooks.covers import *; open('cover.jpg', 'wb').write(create_cover('my title', ['my author'])))"

And you can set whatever preferences you like when using the create_cover function, see the sourcecode for details.

Just what I was seeking. Thanks very much.

[olin-shivers]

Originally Posted by kovidgoyal

I dont see what's so hacky about it. But if you really want to run just the cover generator, do it like this.

calibre-debug -c "from calibre.ebooks.covers import *; open('cover.jpg', 'wb').write(create_cover('my title', ['my author'])))"

And you can set whatever preferences you like when using the create_cover function, see the sourcecode for details.

Kovid-

One more question: can you tell me how to make this code cause SVG output?

-Olin

[kovidgoyal]

covers are generated as raster images, there is no svg output

[olin-shivers]

Originally Posted by kovidgoyal

covers are generated as raster images, there is no svg output

Wait... then why does ebook-convert have a --no-svg-cover flag? I'm confused.

-Olin

[kovidgoyal]

That refers to the wrappedr code used to display the image inside the epub

[olin-shivers]

Originally Posted by kovidgoyal

That refers to the wrappedr code used to display the image inside the epub

Ahh! Thank you, again!

Olin