Quadrupole power-ratios P₂∕P₀ versus the octupole power-ratios P₃∕P₀ of the total images of the different line emissions shown in Fig. 2. The dots represent the values measured for the pGMCA images obtained from the real data, and the crosses the 10th and 90th percentiles obtained with pGMCA on a hundred constrained bootstrap resamplings, with the center of the cross being the median.