Linux: Space on hard drive, and location of files

[Taildragger]

Hello
I am a new user of Xnview, but a long term user of Picasa on Windows. I use Linux (Mint) almost exclusively now and was looking for a good photo management application. I am using Xnview and and liking what I am learning, but I have one concern—SPACE!

I have a 1TB drive divided with 560GB dedicated to Linux. After installing Xnview and it searching our my photos, the hard drive is not 8% more full, which is almost 50GB. My photo file is 131GB. I know that Picasa doesn't copy the pictures, but just makes/keeps a reference to them. So I have 2 questions.

1) Should Xnview have used up that much space? (and does it make a copy of the pictures?)
2) If I wanted to remove the program, what files would I remove (ie, where are the files kept? In Linux?

Thanks in advance.

[xnview]

1) Should Xnview have used up that much space? (and does it make a copy of the pictures?)

no picture files are not copied

2) If I wanted to remove the program, what files would I remove (ie, where are the files kept? In Linux?

Please check in config/.xnviewmp folder to check files used by XnViewMP