images not scaled properly when export to pdf

Images that have a wide width will caused export to pdf to not render the whole image

Steps to reproduce :

1. Create a new page
2. Click Insert -> Image
3. Browse an image with width 1243px
4. Choose the image and click insert
5. Click save
6. Click Tools -> Export to PDF

Attached is the pdf that is being exported and the original image. This can be major for some customer that use images extensively.