require 'iconv'
require 'rexml/document'
include REXML

xmldoc = REXML::Document.new(File.new('/tmp/t.xml'))
puts Iconv::iconv("ISO-8859-1", "UTF-8", xmldoc.elements['//image'].attributes['caption'])
ios = File.open('/tmp/t2.xml', "w")
xmldoc.write(ios, 0)
ios.close

xmldoc = REXML::Document.new(File.new('/tmp/t2.xml'))
puts Iconv::iconv("ISO-8859-1", "UTF-8", xmldoc.elements['//image'].attributes['caption'])
ios = File.open('/tmp/t3.xml', "w")
xmldoc.write(ios, 0)
ios.close

xmldoc = REXML::Document.new(File.new('/tmp/t3.xml'))
puts Iconv::iconv("ISO-8859-1", "UTF-8", xmldoc.elements['//image'].attributes['caption'])