Fig. 6From: Applying spectral fractal dimension index to predict the SPAD value of rice leaves under bacterial blight disease stressMeasurement of the hyperspectral curve length by radius iteration. a Measurement with the initial radius r1. b Measurement with iterated radius rj. c Measurement the last radius rM. After initialization, the radius keeps being updated according to Eq. (5) during iteration. The termination condition is determined by Eq. (7)Back to article page