HUGE Dragonshard mini_image compressed to 634KB

[whoeverxxx]

I downloaded the Dragonshard mini_image at GCW and noticed it was over 1 GB in size, compressed to 634KB with Winrar. I made a much smaller working mini-image for the game but I have no idea how that huge file was compressed like that using Winrar. I'm using version 3.20 of Winrar and when I compress files they are not much smaller than the original. I'll admit I don't compress files much but this makes me wonder if the newer version of Winrar lets you compress files to that extent or if I'm missing something on my version or I just don't know how to use the program enough on the packaging end. Can someone shed some light on the subject?

[GLH]

WinRAR 3.51 is the latest version.
But i think also with this version, you can't compress a normal 1GB image to 700KB.
I think you need another tool to blank out the files in the image, so only the file structure is left (or somethink like this).

[DABhand]

Yeah GLH is correct, its called a Maxi-Image, where a full image was made then data was zeroed out, leaving just the TOC and any topography, I cant remember the name of the application, but it had ISO in the title.

[caki]

They all usually do. Anyone got any documents on the CD data struct? I was making a maxi image, but I zeroed out the wrong crap and poof, corrupt CD.

For DVD its much easier, but Im looking for a way to Maxi a CD image of Civ4.