MATLAB Code for SAR Image Speckle Noise Reduction Using Wavelet and Hybrid Domain Filtering

This MATLAB code implements speckle noise reduction for Synthetic Aperture Radar (SAR) images using a multi-stage filtering approach. The algorithm first applies wavelet-based frequency domain filtering to decompose the image into different frequency components, followed by a cascade of three distinct time-domain filters that operate on the spatial domain. The hybrid methodology leverages both frequency and time domain processing to effectively suppress speckle artifacts while preserving image features. Key implementation aspects include: - Wavelet decomposition using orthogonal wavelets (likely Daubechies or Symlets) for multi-resolution analysis - Thresholding mechanisms (hard/soft thresholding) applied to wavelet coefficients - Three sequential spatial filters (potentially median, mean, and adaptive filters) operating in cascade configuration - PSNR calculation module for quantitative performance evaluation However, the current implementation requires modifications in several areas. The PSNR computation module contains errors that affect accurate quality assessment, potentially due to incorrect reference image handling or normalization issues. Additionally, the wavelet denoising component exhibits implementation flaws, possibly related to improper threshold selection or coefficient processing during the reconstruction phase. These issues need resolution to ensure optimal denoising performance and reliable metric calculations.