Correction: Simplified procedure for efficient and unbiased population size estimation

The images for Figs 3, 4 and 5 are incorrectly switched. The image that appears as Fig 3 should be Fig 4, the image that appears as Fig 4 should be Fig 5, and the image that appears as Fig 5 should be Fig 3. The figure captions appear in the correct order.

Fig 3. Crowd counting dataset.

15 manually annotated point patterns selected at random from the crowd counting dataset. The total number of point patterns in the dataset is 51.

Fig 4. Empirical squared coefficient of error for fixed parameter values.

(A, B, C): Empirical squared coefficient of error of the 51 point patterns in the crowd counting dataset, for fixed sampling fractions f = 0.02, 0.04, 0.06 respectively. Population and sample sizes are shown on the x axis. Blue and red color represent initial number of quadrats n₀ = 50, 100 respectively. Broken horizontal lines correspond to 5%, 10% and 15%, whereas the vertical broken is drawn at sample size Q = 50. (D, E, F): Analogous plots for nonempty quadrats n. Broken horizontal lines correspond to 20, 30 and 50 quadrats.

Fig 5. Empirical coefficient of error for optimal parameter values.

(A): Empirical coefficient of error, obtained with sampling fractions adapted to each of the 51 point patterns considered in Fig 4. Blue, red and green colors represent sample sizes Q = 50, Q = 100 and Q = 200 respectively. Initial number of quadrats was set to n₀ = 100 for all cases. (B): Analogous plots for nonempty quadrats n. The broken horizontal lines are as in Fig 4.