Disk images from II to PC ?

[Zouplaz <user@domain.invalid>]

Hello, I would like to create disk image from 800k floppies and use them 
 with xkegs or kegs under Windows.

I own a IIGS, a PowerMac and two PCs (one under linux, one under XP)

I've allready transfered several images created on the GS :
- I create images on the GS
- transfer them on the mac via appletalk
- then transfer them on linux thanks to netatalk
- then transfer them again to windows if needed

I just would like to skip the step number 1 and create the image 
directly with the Mac.

What application exists on Macintosh that is able to create disk images 
suitable with kegs ?

Thank you