Gradation processing algorithm of digital radiological chest image

Gradation processing technology can enhance display contrast of interested region by using linear or nonlinear transform. Current algorithms generally calculate transform parameters depended on experimental statistical values or some simple image processing method such as histogram analysis. They cannot accord with the human subjective vision mechanism nor can they intelligently acquire required parameters. Therefore, processing results are not very accurate or reliable. We propose a gradation processing algorithm of digital radiological chest images based on region growing segmentation technology. It combines self-adapted segmentation with prior knowledge of directed segmentation, and its computation cost is low. It can perform contrast enhancement of the interested regions more accurately, and accords with the human subjective vision mechanism better.