Converting Graphics to send to a zebra p

I am currently writing a VB project that includes sending images to Zebra printer. The problem is that I need to the Hex representation to the printer in a string. I managed to convert the file to hex and then save it as text so VB could read it in. Now my project is crashing because the file that I am reading, character by character, is so huge. Is there a better way to do this?