Reducing the size of hybrid images

Hello Almighty All,

I tried to create a hybrid Windows/Mac autorun image using hdiutil. I used two files, approximately 64K in size. The first file was visible on Windows, and the second on on Mac.

Everything worked perfectly, and the proper autoplay dialogs were displayed on Mac and Windows. However, the size of the image is 900K.

I tried to experiment with “compact” and “resize” verbs, but this did not help: the size remains to be 900K. At the same time, an ISO (not hybrid, just the Windows one) with no files at all can take as little as 50K.

Is this overhead normal? Is it due to the image being hybrid or one of the FSes being HFS? Finally, would anyone please kindly give a pointer to how to reduce the image size, if this is possible?

Thank you in advance,
KR