Save the Directionality Results window contents to a spreadsheet by copy pasting.So for the pine image up there, one can conclude that the proportion of needle leaves oriented around +60° is at least 25% (however, the image is not completely uniform, which cripples the meaning of this amount value). The ‘Goodness’ column reports the goodness of the fit 1 is good, 0 is bad.Ī study made on artificial images reveal that the ‘Amount’ value as calculated here underestimates the real proportion of structures with the preferred orientation.The real histogram values are used for the summation, not the gaussian fit. The ‘Amount’ column is the sum of the histogram from center-std to center+std, divided by the total sum of the histogram.The ‘Dispersion (°)’ column reports the standard deviation of the gaussian.The ‘Direction (°)’ column reports the center of the gaussian.The highest peak is fitted by a Gaussian function, taking into account the periodic nature of the histogram.On top of the histogram, the plugin tries to generate statistics on the highest peak found. The orientation map flag will cause the orientation map to be generated see below.This table can be exported as a CSV file thereafter see below. The result table flag will generate a table containing all result value to be displayed.The debug flag, if set, will cause angular filters and power spectrum to be displayed.This option was added to avoid having peaks at +90° split at the borders of the histogram. Angles will run from this value to 180° plus the starting value. The starting angle (default:-90°) for analysis.The number of bins (default: 90), that will partition the 180°.That is: 0° is the East direction, and the orientation is counterclockwise. On top of that, a minor peak can be seen around 0°, reporting the main branch orientation.Īngles are reported in their common mathematical sense. This is well detected by the plugin, which reports two main peaks at 60° and -60°. Images with completely isotropic content are expected to give a flat histogram, whereas images in which there is a preferred orientation are expected to give a histogram with a peak at that orientation.įor instance, in the pine tree branch pictured above, the needle shaped leaves exist in 2 populations, one with a preferred orientation at about 45°, and another one with preferred orientation around -45°. It computes a histogram indicating the amount of structures in a given direction. This plugin is used to infer the preferred orientation of structures present in the input image. If you’d like to help, check out the how to help guide! Usage The content of this page has not been vetted since shifting away from MediaWiki.
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