Fig. 3From: Four-dimensional measurement of root system development using time-series three-dimensional volumetric data analysis by backward predictionSBI-ICP registration. a A x–y slice of an X-ray CT image. Image size is 307.2 mm × 307.2 mm. The yellow arrowhead indicates high intensity signals derived from minerals. b A point cloud based on high intensity signals derived from minerals. The point cloud was designated as SBI (soil block identifier). c ICP (iterative closest point) registration with time-series X-ray CT volumes. d Overlaid top-view projections of 21 RSA-segmented volumes without and e with ICP registrationBack to article page