Prebiased peak extraction algorithm with linear error compensation for chromatic confocal microscopy

Chromatic confocal microscopy (CCM) suffers spectral peak localization errors due to nonlinear coupling between physical peak shifts and centroid estimates. These inaccuracies arise from discrete sampling by finite-sized pixels and non-ideal peak extraction, presenting inherent limitations in conventional methods (e.g., centroid algorithms). To overcome this, we propose a pre-biased peak extraction algorithm (PPEA) that realigns spectral peaks to a zero-reference position. This linearizes residual errors relative to true displacement, enabling closed-form analytical error compensation. Simulations confirm robustness for symmetric/asymmetric spectra. Experiments show 12-fold accuracy improvement: error reduced from 0.5 μm to 0.04 μm within a 1 mm range, demonstrating strong potential for precision measurements.