image res

So I downloaded the perfect image I need for a cd design. It is a tff at 3000 res (yikes). Problem is I can only use it in 175 resolution for getting films made. But when I reduce the resolution so goes the size of the image and it is about 1/2 as big as I need it then. Increasing size just makes the pixels jump out. Is there anyway to decrease the res without reducing the size so much or is this a retarded question.
Any help would be greatful.
thanks....

In photoshop...

IMAGE>IMAGESIZE>

change the "resolution" to whatever you want...

the pixel size is going to decrease... but the physical size will stay the same.

You can also set the "fixed target size" on the crop tool to crop at the "size and resolution" you choose.... (just be sure not to take a crop larger than your original area if resolution doesn't permit.)