What if my device does not provide uniform lighting throughout the image?
When grading a linear bar code symbol, it is important that the illumination is constant across the image. If this is not possible, for example when used in a handheld scanner, it is possible to produce a grade using a limited subset of the categories normally used to grade the symbol. In this case, it is recommended that only the decode and decodability scores are used to grade a linear bar code symbol.