Se simpler way to go, probably, was to print the images you have and use a keyboard connectable scanner to parse the barcodes you have.
: You need to use the width of the long bar (not it's height) to know if a bar is a single binary digit or more than one. A slim bar is a digit, a large on is two, or even three or four digits. For example, 6 using L-Code have 4 consecutive "1" digits (black bars) and using G or R-Code have the same 4 but "0" digits (white bars).