Agreed - the skins would have to take over the slide image scaling and cropping. No thank you!

The ThemeImageProcessor() method in the core doesn't apply any of the image edits to the theme image. So, you can crop it like crazy, invert the colors, apply watermarks, whatever. But the theme image is generated from the unmodified image, as added to the project. Just watch the "theme image" box on the lower right as you make edits to the image. Its Explore thumbnail changes, but the theme image and its crop mask do not.

That may not be perfect, but it's a reasonable approach to take. The cropping requirements for a regular image in the gallery aren't likely to be the same as the cropping requirements for that same image when used as a theme image. It's not possible to get them both right.

The theme image crop mask is what gets applied to the image when it's used as the theme image. If regular cropping were also applied, how would you figure out how to do that? Which one goes first? Regular cropping for the thumbnail and slide versions of the image, theme image cropping for the theme image. You can't mix the two.

If a user wants to apply cropping to an image for its use as the theme image, he needs to pre-crop it. He could add it to a project with the NoPages skin, set the image bounds crazy large (like 10000x10000), apply cropping and whatever other image editing he wants to do, hit Make Album, and grab the output slide image. Then add that image to the real project, exclude it, and then select it as the theme image.

ETA: This is why I try to avoid "rolling my own."

For a bundled, in-house skin, I'm not sure that's a good idea from a company standpoint, or for future maintainability.

BTW, you can do B&W background images with CSS.

background-color: #ffffff;
background-blend-mode: luminosity;

By changing the background color, you can get some weird effects. Not good, but certainly interesting.

Wouldn’t method 3: https://jalbum.net/help/en/Sample_scripts#Theme_images
Do the job, by changing the themeFile reference and the dimension bounds to create the other images.

David has fixed the bug with the cropped image dimensions. Use Tools / External tool / jAlbum core update to get the latest jAlbum, v39.2.1.

The source of the theme image is supposed to be large enough after cropping - 920x240 px in this case - to avoid blurred theme images.

I can confirm that the bug with the cropped image dimensions has been fixed with the update.

Thank you for your support!!!

PS: I still have the problem with the fileiterator code. But that's a different topic, and I'll probably open another thread.