Okay,
Many times in SQL Server, folks won't actually store images directly in the database (although that is quite possible.) Instead, what they will do is store the path&file name of the image in an ordinary varchar column. Something like 'c:\products\pictures\widget.gif'. Then it becomes the job of the application (ASP, whatever...) to read that column to get the path&file name, and then retrieve the image from the disk.
I was assuming (maybe incorrectly) that this is what you were doing. So when I said this:
Select SUM(ImgExists(ColumnWithPath)) as ExCount
From Products
I thought you had a column in your table like I have described.
If this is not what you were looking for, then my apologies. (It's too bad, because I actually have it working!) Would you like to describe further what it is you are interested in?
bperry