Hello,

I would like to add image titles above each thumb using bxslider_thumb_nav extension.

I can add the file name using
$imgobj->getFileName();

but using
$imgobj->getImageTitle();
does not work.

getImageTitle() is located at template-functions.php - maybe the reason why this function is not available with bxslider extension.

Use $imgobj->getTitle() or just getImageTitle()

It's by the way explainded as an example here:
https://www.zenphoto.org/news/zenphotos-object-model-framework/

You can always consult the documentation here:
https://docs.zenphoto.org/1.5.x/class-Image.html

And note about class inheritance of parent classes.

Thank you for your help, it is OK now :

I will print your documentation (your links) for reference !