Default [Q] issue with extracting system.img from an official source

ok, ima try to make this short and sweet. Im attempting to extract the contents of system.img from an official samsung firmware using unyaffs2
this is quite literallly the FIRST time using my android skills since setting up my linux laptop.
ive done the following so far
running ubuntu 10 something
android sdk, eclipse
downloaded two versions of yaffs neither work as i would have expected.

now, trying to extract the system.img from this file (samsung note 3 kitkat official firmware)
https://doc-04-5g-docs.googleusercontent.com/docs/securesc/ha0ro937gcuc7l7deffksulhg5h7mbp1/met8j7ju751f78fpes2risgambd0mblc/1390788000000/16903193897035115666/*/0B84fZ-6xuKyyMmRMTHhjMldINDA?h=16653014193614665626&e=dow nload
im running into this error

image size is not a multiple of 2048 64

it continues to extract the files saying each one has failed and then into the folder i specified there are a couple of files, none of which look recognizable or usable.

what am i doing wrong here?