If I understand you correctly - You want just one channel separate from everthing else.


Go to the channels window, right click on the desired channel and click duplicate channel:

On the duplicate window choose new file and you'll get a regular layer on a new file



How to get three grayscale images from a RGB photo in PS?
I have trouble understand how to translate SQL into LINQ. I would like to do the following but can't figure out how to get the Group By to work

var query = from s in Supplier
            join o in Offers on s.Supp_ID equals o.Supp_ID
            join p in Product on o.Prod_ID equals p.Prod_ID
            where s.City == "Chicago"
            group s by s.City into Results
            select new { Name = Results.Name };


I just need to do something simple like display the product name of this simple query, how does the group by work with joins and a where?
