lightbox embed <img>

Dear：
In admin/config/content/formats，
with the Image resize filter：
1. i checked :If resized, add a link to the original image. Optionally, give it the class:

2. and/or a rel attribute：
add ：lightbox

so ，If i add img and change the size by imce insert box， now I can click the img to show full size bylightbox.

but, I remove the width/height to a class，Then it can work.
the is no link to show lightbox.
unless， I add <a href=" " ref="lightbox" ><img ></a> for <img>
But， I don't want to add <a> for img every time.

so,Is there any soluation?
thx.