Position of crobbing area for thumbnails

When I crop an image manually, the top left corner of the crop area is the top left corner of the original. How are the images cropped when I upload a new image? I want to make sure the center of the crop area is in the center of the image.

MoreGallery does indeed assume you’ll want the center of the image, in as large as a box as what fits on the original image, and as allowed by your crop configuration.