Force image resize on upload with Products Module

[Mich-adg]

Hi,
i use the Products Module on a website, with 6 images fields. If i try to upload 6 images (taken with a smartphone) that are more than 8 mb, i got an error (blank page!). So i must send images per 2 or 3... boring !!
Is there a way to force an image resizing when uploading? Or in anyway to inform the user that the global height is to high (than 8 Mb) ?
Thanks for any help or suggestion.