Underwater Image Enhancement by Rayleigh Stretching in Time and Frequency Domain
Yuting Peng, Chi-Weng Chang, Mong-Shu Lee · 2019
Image restoration and enhancement play an important role in underwater image applications. How to solve the negative gloomy underwater effects resulting from scattering and color distortion has become the key issues. In this study, we proposed a Rayleigh stretching-based image enhancement method. The method includes a few steps which are background color correction, Rayleigh stretching in time domain, discrete wavelet transform with Contrast Limited Adaptive Histogram Equalization (CLAHE), contrast adjustment, and sharpening. Experimental results through both the qualitative and quantitative analyses demonstrate that our approach greatly improves visibility and contrast and obtains best values with respect to entropy and underwater image quality measure (UIQM), respectively.