How to Use Image from Table In Custom Reports(Excel Output)

Hi all, i want to know complete method on how to use image from table and call them in my custom Report,as currently i am calling Blog file type image directly to Report Builder and when number of rows increases shows heap size error on java concurrent,kindly tell which is best method to display images either from path or from Blog to Clog conversion,kindly tell complete method on how to use images in Custom reports,thanks.