If you put an image file in a folder outside the web root,
you can then use a cfm program to display the image.
For example, if you create showpic.cfm as this:
<CFSET fpath="D:\files\images">
<CFSET fname="myimagefile.jpg">
<CFCONTENT TYPE="image/jpeg" FILE="#fpath#\#fname#"
DELETEFILE="No">
You display it as IMG SRC="showpic.cfm"
If this is placed in a directory with an application.cfm and
log-in protection, it should restrict access to your images.