greguh

thanks for such a quick reply !
I was finally able to remove the 150×150 default size by using “Simple Image Sizes” plugin + the Force Regenerate thumbnails that you recommanded (nb: modifying Setting>Media Thumbnail and the Regenerate thumbnails did not work).

Thanks a lot !

To close the post !

thanks again

@josearcos thanks a lot for this answer.

Indeed I succeeded to run the script using jQuery as you can see on this Fiddle
https://jsfiddle.net/szan6shz/4/

thanks again