Contrast enhancement in chest X-ray imaging using exposer region-based modified adaptive histogram equalization (ERBMAHE)
摘要
Enhancing chest X-ray (CXR) images is crucial for accurate clinical diagnoses. Conventional methods, like histogram equalization, often wash out details and cause intensity shifts. This study proposes a novel exposure region-based modified adaptive histogram equalization (ERBMAHE) technique to address these limitations.
MethodsERBMAHE divides CXR images into underexposed, well-exposed, and overexposed regions using our group’s 9IEC algorithm. The well-exposed region is further subdivided, creating five histograms. A novel adaptive probability density function (PDF) and power-law transformation are applied, enhancing contrast through modified HE equations. A fast local Laplacian filter improves detail while maintaining uniform illumination.
ResultsTested on 600 Kaggle CXR images, ERBMAHE outperformed six techniques, demonstrating improved illumination, detail enhancement, and naturalness. It achieved higher metrics such as discrete entropy (DE), peak signal to noise ratio (PSNR), absolute mean brightness error (AMBE), and structural similarity index (SSIM), with qualitative analysis validated by a doctor’s survey.