Why do the Image Capture Extension and softwareupdated processes consume so much memory? I recently updated my 2008 MB Pro (2 GB RAM) to Yosemite from 10.6 and I've found that it's often unusably slow. After keeping an eye on Activity Monitor over a couple weeks, I notice that the Image Capture Extension and software updated processes are often using over 400MB of RAM, 95% of which is compressed. 

Quitting the processes seems to make the system more responsive, but I assume that these are supposed to be running in the background.

The only applications I usually have running are Safari/Chrome, Textmate and LibreOffice. I've been closing app's from the bar when I'm not using them.

Are there any settings I can tweak to change this behaviour?
Could it be a bug? (I've noticed similar complaints elsewhere online)

Notes:


I have a relatively large iPhoto library, but I don't leave the program running
No peripherals (usb keys, cameras, storage, etc) are physically connected


Update:

I did a firmware restart several weeks ago and the Image Capture Extension has been behaving so far. softwareupdated continues to have high memory demand, the process regularly ends up with 400+MB of compressed memory. I suspect that at least some of my problems are related to (un)gzip constantly running.
Since I upgrade my late 2009 iMac (4GB memory) to Yosemite, the system had not been performing well. It would be slow at time particularly after it had not been rebooted for a a day or more. In the Activity Monitor I noticed the it Image Capture Extension was steadily growing to become a major user of memory, and the memory pressure was in the yellow as the extension used more memory. I could not determine what program or process was causing this. I then installed two 4GB memory boards increasing my memory to 12GB. Now the Image Capture extension stays at a low value (25-50MB) and does not grow, and the memory pressure stays in the green. Memory is now cheap, your 2GB is likely your problem.