Few observations:
1. You should bing grid with datatable instead of dataset
GridView1.DataSource = ds.Tables[0];
GridView1.DataBind();
2. I see you are supplying textbox string value for image field. Is that what you intend to do? if you are updating an imagepath then that looks ok or else the code for updating an image does not exists all together.
Use Visual Studio DEBUGGER and step through the code to see if the query formed is correct and has all that is needed. Run the same raw query in Db and check the changes. Everything should be same.