Texture Enhancement Method of Oceanic Internal Waves in SAR Images Based on Non-local Mean Filtering and Multi-scale Retinex

Synthetic aperture radar (SAR) remote sensing is an important tool to observe oceanic internal waves. However, due to the imaging mechanism of the oceanic internal wave phenomenon, the texture details of oceanic internal waves in SAR images are often not obvious enough, which affects the subsequent applications. To solve this problem, a texture enhancement method of oceanic internal waves in SAR images is proposed in this paper, which is based on non-local mean (NLM) filtering and multi-scale Retinex (MSR). Firstly, the NLM filtering is performed to reduce the effect of speckle noise on texture enhancement. Then, the MSR is adopted to process the filtered SAR image to enhance the texture features of oceanic internal waves. Based on the real SAR images of the Gaofen-3 satellite, the experiment of texture feature enhancement of oceanic internal wave SAR images is carried out, and the experimental results demonstrate that the proposed method can effectively suppress the image noise and significantly enhance the internal wave texture.