基于HSI空间的Retinex低照度图像增强算法

Abstract

低照度环境下拍摄的图像往往会出现细节模糊不清的情况，传统的Retinex算法可以有效提高图像质量，然而当图像亮度整体较低时可能会出现过增强现象。为了改善低照度环境下拍摄图像的质量，本文提出了一种基于HSI颜色空间的改进的多尺度Retinex图像增强算法，采用引导图像滤波消除应用Retinex算法所产生的“光晕伪影”现象，并利用原图像的亮度信息对多尺度Retinex算法增强后的图像进行了亮度重构，有效地抑制了过增强等失真现象，进一步提高了图像增强质量。实验结果表明，本文算法与传统的多尺度Retinex算法相比在低照度图像亮度增强、对比度增强和图像细节信息保护方面具有更好的表现效果。 The images which are captured in low brightness environment are often blurred. The traditional Retinex algorithm can improve the quality of image; however enhancement phenomenon may occur when the image brightness is low. In order to improve the quality of captured images in brightness environment, an improved multi-scale Retinex image enhancement algorithm based on HSI color space is proposed in this paper. In this algorithm, the guide image filtering is used to eliminate the “halo artifact”. The intensity of enhanced image based on multi-scale Retinex algorithm, is reconstructed by applying the intensity of original image. This effectively suppresses the distortion such as over-enhancement, and further enhances the image quality. Experimental results show that for low-luminance image the proposed algorithm has better performance than the traditional multi-scale Retinex algorithm in brightness enhancement, contrast enhancement and image detail information protection.