Bug or normal behavior?

Hi, all

I found when I view a 4M jpg file with eog-3.2.2, it consumes more
than 100M memory (memory information is obtained with Alt+SysRq+M).
But everything is OK if I use firefox to view them. So, I want to know
whether this behavior is normal, or there is a bug in eog? It cause my
PC crashes when I view several images together...

Below are files for testing, I use Arch Linux with kernel 3.2.5.
http://dev.lemote.com/filebox.cgi?p=download&f=DSC_1660.JPG
http://dev.lemote.com/filebox.cgi?p=download&f=DSC_1670.JPG

Best regards,
Huacai Chen