Supplementary Figure 1: Annotator training, neurite length measurement and skeleton consolidation.

(a) Tracing speed per annotator during training for flight mode (magenta) and ortho mode (black) tracings (average data shown in Fig. 1h) (b) User-preset maximum movement speed per annotator during training for flight mode (magenta) and ortho mode (black). (c) Tracing speed per annotator during test reconstruction in flight mode (magenta) and ortho mode (black) (average data shown in Fig. 1i) (d) User-preset maximum movement speed per annotator during test tracing in flight mode (magenta) and ortho mode (black). (e) Histogram of total previous tracing experience of all annotators in training experiment (Fig. 1h). (f) Skeleton path length measurement examples: axon traced in ortho (black) and flight (magenta); magnification in f_2a shows higher skeleton node density for flight-traced aonxs; f₃ and f₄ show comparison of skeletons smoothed using NURBS of node order 4 (NO 4, dotted) and variable node order (NO var, dashed). See Methods for details. Scale bars apply to f₁..f₄ (from top to bottom). (g) Comparison of path length measurements for 10 axons traced in ortho and flight mode. For calibration of optimal path length measurement, the average of 7 to 21 tracings per axon was used. Note that variable NO method renders measurements in ortho and flight mode similar to about 2% path length variability; and all path length measurement methods vary by no more than about 15-20%. See Methods for details. (h) Vote histogram from RESCOP algorithm (Helmstaedter et al., 2011) based on ortho tracings published in (Hua et al., 2015), ortho and flight tracings from the training experiment (Fig. 1h), respectively (see (Helmstaedter et al., 2011) for details); total vs. agreeing votes. (i) Decision error p_err(T,N) for same data, with optimum (white dotted line) and majority vote (black dashed line) decision threshold, see Methods and (Helmstaedter et al., 2011). Cited references: Helmstaedter et al. (2011) NatNeurosci 14:1081. Hua et al. (2015) Nat Commun 6:7923.