I try to add one image to my workbook/worksheet.
The Code :
wb.add_worksheet(:name => \"Doc1\", :page_setup => setup, :print_options => opt
An example on https://pramodbshinde.wordpress.com/2013/12/29/design-spreadsheets-using-axlsx-in-rails/ show the following line of code
img = File.expand_path(Rails.root+'app/assets/images/result.png')