Q: ITMS-90228 - IMAGES LARGER THATN 4MP (I CHECKED EVERY IMAGE IN MY BOOK AND THEY ARE WITHIN SIZE LIMITS)

when i try to upload my epub file thru iTunes producer...i am getting the following error. don't know how to resolve it --

ITMS-90228 - IMAGES LARGER THATN 4MP (I CHECKED EVERY IMAGE IN MY BOOK AND THEY ARE WITHIN SIZE LIMITS)