Writing an imgae tag in to_xml

Hi,
I am trying to create an pdf report by using ruby jasper pages. For that
I have written customer_list.rxml file like this:

xml.instruct!
xml.customer_list_result do
xml.invoice_customers do
@customers.each do |customer|
xml <<
customer.to_xml(:dasherize=>false,:skip_instruct=>true,:only=>[:id,:name,:city],:root=>“customer”)
end
end
end

I want to add an image tag into this xml data, so that image will be
displayed on the pdf.
I have customer_image field in customers table.
Can anyone help me out for this?

Thanks,
Tushar