Figure 3:

Image processing and segmentation strategy for microglia quantification. The original image (A, enlargement Ai) was first converted to grayscale with maximum intensity projection and inverted, followed by denoising, removal of uneven background illumination, fast Fourier transform bandpass filtering, image sharpening, and rescaling to prepare a processed image (B, enlargement Bi) for segmentation. Soma locations were marked as regional minima to produce a composite image for watershed segmentation (C, enlargement Ci), which yielded a segmented and labelled image (D, enlargement Di) where the cell perimeter defined by the blue boundary, and the skeletonized microglia by the red line.