Resize TIFF images to certain size in MB and DPI

[d3x]

Hi,

I have a question regarding changing the size of a TIFF image.
I want to be able to change the size of a 60mb TIFF image to at least 12mb.
But at the same time I want the DPI to be even 100.

So for example:

I have a 60mb TIF file, when resized it's 12,4mb and the DPI is 700.
I have a 47mb TIF file, when resized it's 12,7mb and the DPI is 800.
I have a 58mb TIF file, when resized it's 12,3mb and the DPI is 3500.

The mb is always at least 12mb and the DPI is always 100,200,300,400,500 etc.
The important part is the DPI, if the image is 12mb exactly or 12,35 doesn't matter.

Is there a command for this?
Can someone point me in the right way?

[snibgo]

DPI, dots per inch, has no impact on the filesize. Set it to anything you like.