If any kind of jbr to jp2 conversion is even possible, it would be something like export or brushes (.jbr file) from Corel PaintShop Pro to save it as common JPEG2000 picture. But in broad sense this might be the use of particular brush for a new or existing picture, which is more of import of the brush in to the software. Be as it might be, you will require Corel PaintShop Pro in both cases.
Updated: August 7, 2023