(a) Optical configuration. (b) Image formation of two object points observed for two conditions: Δz = 50 µm, 3640 cm−1 and Δz = 0 µm, 1070 cm−1. Generation of aberrated images of `π' and their reconstruction for (c) Δz = −50 µm, 2100 cm−1 and (d) Δz = 0 µm, 3640 cm−1. Generation of aberrated image of `α' and its reconstruction for (e) Δz = 50 µm, 3640 cm−1. The green, blue, yellow and pink borders indicate PSF, object, aberrated image of object and reconstruction, respectively. The symbols `⊗' and `
*' are 2D convolution and 2D non-linear correlation for (a = 0, b = 0.54) operators.