Radiographs enhancement based on unsharp masking and Gray-level Grouping

Contrast enhancement has played an important role in image processing. A variety of enhancement algorithms now existing mainly focus on the overall contrast of digital images while sometimes we may wish to know much about details such as the lung capillaries and so on. The unsharp masking image enhancement techniques allow enhancing very small structures but are not accessible for larger size objects. Gray-level Grouping (GLG) method is effective to optimize the overall enhancement. In addition, multi-scale decomposition of the images has been proven to be capable and efficient method to cope with digital images. So we combined all of the three methods to enhance the digital radiographs. The experiment shows that contrast and details have been improved greatly.