code: public String toDataURL(final boolean filtered)
      {
          if (false == isLoaded())
          {
              return null;
          }
          if ((m_fastout) || (false == filtered))
          {
              final ScratchPad temp = new ScratchPad(m_jsimg.getWidth(), m_jsimg.getHeight());
  
              temp.getContext().drawImage(m_jsimg, 0, 0);
  
              return temp.toDataURL();
          }
          else
          {
              return m_filterImage.toDataURL();
          }
      }
docs: Returns the "data:" URL
  
  @param mimeType If null, defaults to DataURLType.PNG
  @return String