Toward a Dual-Input Feedback Speckle Imaging Framework Under Multiple Light Sources in the Presence of Ambient Illumination

Recovering high-quality images from low-quality speckle patterns remains a core challenge in scattering imaging, especially under narrowband illumination with ambient light interference and broadband illumination. This paper proposes a dual-input synchronous transmission architecture: after Correction-Smoothing-Phase Optimization (CSPO) preprocessing, two data streams are parallel-fed into Phase-Aligned Coherent Summation (PACS) for efficient and high-precision reconstruction with adaptive fusion, breaking the single-path limitation of traditional methods and balancing imaging efficiency and quality. Additionally, an adaptive enhancement factor feedback mechanism is designed for Median-Unsharp Sharpening Enhancement (MUSE) to dynamically adjust Median Filtering (MF) and Unsharp Masking (USM) parameters, achieving adaptive balance between noise suppression and detail enhancement and improving robustness under extreme lighting. In PACS, a dynamic reference update mechanism is introduced, combined with fixed amplitude to realize iterative phase optimization, effectively suppressing speckle noise and boosting the signal-to-noise ratio of reconstructed images. Experimental results show that the proposed method achieves favorable restoration performance even at a SNR of −8.7 dB under narrowband and broadband illumination with spectral bandwidths of 100 nm, 200 nm, and 280 nm (FWHM), and significantly improves image quality in unknown scattering media, showing great potential for robust speckle reconstruction.