γ Radiation Image Enhancement Method Based on Non-Linear Mapping

For the problems of darkness, insufficient contrast, and color cast in the images captured by CMOS image sensors in the <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> radiation environment, this paper proposed a joint contrast improvement and color cast correction approach for the <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> radiation image enhancement, which improved the image effects from enhancing detail expression and color expression. For the problem of overall darkness of <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> radiation image, we first utilized logarithmic mapping to improve the image brightness. Secondly, for the insufficient contrast of image details, a contrast enhancement method with an adaptive Gamma coefficient is proposed, which adaptively adjusts the image brightness at the pixel level, so that the image detail expression is more in line with the human visual characteristics (HVC). Lastly, the color level remapping method is exploited for color cast correction. Extensive experiments are conducted on the <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> radiation images collected in the Co60 environment. With the help of the proposed method, we can achieve the best results in quantitative and visual comparison. Experimental results demonstrate that the proposed method enjoys state-of-the-art performance in <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> radiation image enhancement.