Insert Picture data To Binary Data Column

Can anyone please offer some advice for a novice? 

In addition to my methods and properties for uploading full size images i have this code which i am using to try and create a thumbnail image of the uploaded image
and insert that into a binary column in my database. I have tried several methods but i keep getting an invalid argument error cannot convert byte to int when im trying create a byte array to pass to the parameter. The code is in the upload btn click event.
                         

                    
                    //reading the picture from the upload control memory stream
      ...