Fig. 4From: A pillar-based microfluidic chip for T-cells and B-cells isolation and detection with machine learning algorithmOriginal image 1(a), horizontal and vertical derivatives of image 1(b), orientations of gradients overlaid on each pixel 1(c), orientations gathered into histograms and block normalized 1(d). Histogram of gradient features overlaid on cells 2(a, b), noise 2(c) and background image 2(d)Back to article page