Fig. 2.

Acquisition and alignment of images at the experiment. (a) A schematic of the experimental setup for NIR image acquisition. (b) Image sequence stored in the memory for further analysis. (c) The inset in (b) as ROI is cropped and showed for geometrical correction. Upper row represents the original cropped raw images and lower row shows the geometrically corrected images. A square dashed box is drawn on the raw image by considering the dark mark at its center. Scale bar = 10 mm. (d) Quantitative analysis of the original cropped and corrected image are shown by a normalized gray value inside the dashed box centering the dark mark as shown in (c).