Figure 11From: Probing crowd density through smartphones in city-scale mass gatheringsCalibration regression. Linear regressions of the calibrated crowd densities ρ ˆ Crowd and the crowd densities ρ Crowd obtained from video footage. Results are shown for different kernel radii R. A perfect regression would correspond to the diagonal axis. Additionally, the figure also shows the scatter plot of the calibrated data points for the case of R=55 m.Back to article page