A new binarization method for PDF417 bar code by camera phone

The bar code images captured by camera phone have natural disadvantages in the complex environment, such as blur, low contrast, high brightness, etc. Therefore, it is difficult to decode the bar code successfully without preprocessing. Binarization plays an important role in image preprocessing. In this paper, we regarded time complexity and adaptability under the complex environment as a standard for binary PDF417 bar code image captured by camera phone. Based on this, we proposed a novel algorithm, and compared with several classic and commonly-used binary methods. The new method integrates the advantages of the global threshold, the local threshold and the adaptive threshold and gets a balance between the time complexity and adaptability under the complex environment. The experimental results have proved the validity of this new algorithm.