Is it possible?

Hi guys, okay I just dig a lot together with Mr. Google regarding of resizing and reducing images file. However, what I'm facing is not just a typical image file it is a satellite map image which is a ".pix" file.

So it is the same what i want to achieve i want to reduce the file size of my satellite map image (.pix file), can anyone show me or point me on how to achieve this.

Thank you in advance.