Manipulating .tif files in Land Desk Development

Ok,

I have the following challenge. I'm using Autocad 14 with LDD version 2 (I believe).

I have 5 georeferenced aerial photos of a street alignment. They are in .tif format with associated .tfw files.

I have autocad line work of the street and surrounding property lines. This is in a separate drawing and is also georeferenced (meaning that the photos and line work overlay perfectly).

I need to combine the 5 photos together. Crop out the areas I don't need and then overlay the combined aerial photo onto the autocad line work.

Ideally I want to end up with a single new .tif file of the combined aerial photos that I can overlay. This is because file size is a problem as each photo is 100megs in size and it takes forever to load.

I have been sucessful in getting the photos in and cropped but no matter what I do I can't create a new combined .tif file. The original files are always being referenced.

So in other words:

What I have been able to do:

Line work

-referenced to-

Combined aerial photo (cropped as I need)

-referenced to-

5 original photos


What I want:

Line work

-referenced to-

Combined aerial photo

-which is referenced to nothing but was created from the original 5 photos-

Sorry about the long message. Any suggestions?

-Garry