Section: New Results

Phase estimation in Differential Interference Contrast (DIC) microscopy

Participants : Lola-Xiomara Bautista Rozo, Laure Blanc-Féraud.

We present a gradient-based optimization method for the estimation of a specimen phase function from polychromatic DIC images. The method minimizes the sum of a nonlinear least-squares discrepancy measure and a smooth approximation of the total variation. A new formulation of the gradient and a recent updating rule for the choice of the step size are both exploited to reduce computational time. Numerical simulations on two computer-generated objects show significant improvements, both in efficiency and accuracy, with respect to a more standard choice of the step size.

Figure 2. Data and results for the cone object. From left to right: true object, noisy DIC color image taken at angle ${\tau }_0=0^{\circ }$ and SNR = 4.5, reconstructed phase and the relative error versus the number of iterations.

Figure 3. Data and results for the cross object. From left to right: true object, noisy DIC color image taken at angle ${\tau }_0=0^{\circ }$ and SNR = 4.5, reconstructed phase with and the relative error versus the number of iterations.