Fractal characterisation of the cork cambium in Fraxinus angustifolia Vahl. depending on image caption distance

摘要

This study aimed at characterising and analysing the geometry of bark in the species Fraxinus angustifolia Vahl. (ash) through fractal analysis. Binarised images of the ash bark captured from a caption distance between 10 and 50?cm every 5?cm were analysed through box-counting. Depending on the pixels analysed (black and white - BW, black + black and white - B+BW, and white + black and white - W+BW) we obtained fractal dimensions D_(BW), D_(B+BW), and D_(W+BW), respectively. There was a high positive correlation between fractal dimensions and image caption distance: r = 0.895 for D_(BW), r = 0.787 for D_(B+BW), and r = 0.820 for D_(W+BW), respectively. The relationship of interdependence between fractal dimensions and image caption distance was described by second degree polynomial equations with statistic safety, as follows: R~2 = 0.882, p = 0.00165, F = 22.371 for D_(BW), R~2 = 0.918, p = 0.00055, F = 33.498 for D_(B+BW), and R~2 = 0.932, p = 0.00031, F = 41.292 for D_(W+BW), respectively.