Bright stretching method for image enhancement of sputum specimen

Abstract

Tuberculosis is a serious disease caused by infection of germ Mycobacterium tuberculosis. Sputum specimen analysis is a common method for TB bacilli detection. The Ziehl-Neelsen stain is a special stain used to identify the TB bacilli. However, there are some factors that may degrade the quality of contrast and brightness of sputum TB slide image that a blur, too bright or too dark through many processes such as exposure and staining process. Therefore, image enhancements are necessary to improve the quality of sputum TB slide image in term of contrast and brightness. This paper proposes one method for image enhancement; bright stretching algorithm using Visual Basic software version 2010. Bright stretching produces the better enhanced sputum TB slides images when threshold value is greater than bright stretching factor. Value of bright stretching factor is 175 and value of threshold is 200, which the difference between value of bright stretching factor and threshold is 25, produced the better enhanced image in terms of contrast and brightness of Ziehl-Neelsen sputum TB image. The results show that bright stretching method is successfully improved the quality of Ziehl-Neelsen sputum TB image in terms of contrast and brightness.