Speckle reduction in digital holography based on cosine similarity and polynomial interpolation

Speckle noise caused by coherent light often compromises the quality of digital holography reconstructions. To address the limitations of our previously proposed denoising method based on cosine similarity, we introduce a new technique in this paper to further enhance the image denoising performance. Our approach uses image information in four directions surrounding the target pixel and applies appropriate polynomial interpolation to accurately fit the pixel. Experimental results, including both qualitative and quantitative analyses, show that this approach can effectively reduce speckle noise while preserving the original image details. Across various metrics, this method based on cosine similarity and polynomial interpolation offers clear advantages over general image-processing techniques.