def to_images
      image_map = []
      self.each do |file|
        begin
          image_map << ImageFile.new(file)
        rescue Exception => e
         $stderr.puts "WARNING: skipped file - #{e.message}"
        end
      end
      image_map
    end
def to_images
      image_map = []
      self.each do |file|
        begin
          image_map << ImageFile.new(file)
        rescue Exception => e
         $stderr.puts "WARNING: skipped file - #{e.message}"
        end
      end
      image_map
    end
Public: map the filelist to ImageFiles, handling any errors.
   For now, this just reports errors to STDERR so they can be noted.

 Returns an Array of ImageFiles.