A New Bi-Level Representation Technique of Continuous Tone Pictures Based on Multistage Division Quantization Method

Abstract

In this paper, we proposed a new method. In our proposed method, the whole area is divided into the blocks composed of 2x2 pixels, and determined a total value of pixels in each block. Secondly, the value is divided into the blocks composed of the maximum pixel value. The quotient means the number of white dots. The position of the white dots is decided by the order of pixel value. The rest is saved for the next process. Then, neighbor 2x2 blocks are merged and the above-mentioned distribution process is recursively applied. Thus, the position of white dots is progressively determined, that is to say, this algorithm works as bottom-up process. In addition, we consider improvement of our proposed method. As a result, our proposed method outperforms the Multistage division quantization method(MDQ) in the gradation region.