二维码PDF417的国标，是很好的学习标准。-PDF417 two-dimensional code of GB, is a good learning standards.

MIT人工智能实验室的目标识别的源码,本科毕设要求参见标准测试模型，计算时间和二维直方图。- MIT Artificial Intelligence Laboratory identification of the target source, Undergraduate complete set requirements refer to the standard test models, Computing time and two-dimensional histogram.