Volumetric Analysis using Graphic Double Integration

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Documentation for package ‘gdi’ version 1.4.1

Help Pages

cscorr Measure and analyze cross-sectional geometry
fdetect Tool to help determine which threshold value and method to use with measuresil() or cscorr(). The function analyzes all pixels along the edges of the image to determine the background colour, to help with deciding on appropriate settings and avoid errors introduced by inappropriate settings
gdi Estimate volume using Graphic Double Integration.
hCOM Finds the horizontal (x axis, i.e. the axis vertical to the cross-sections) position of the center of mass (COM) of the volume. Experimental; only valid for "raw" gdi results with segment volumes approximated as elliptical prisms, or for manually supplied segment COMs. COM is calculated as a weighted mean of all segment COMs, with the segment mass as the weighting factor.
imghist Simple histogram analysis for all colour values in an input image. Can be used to help assess whether a chosen threshold value is appropriate for differentiating the silhouette from the background, or for general.
measuresil Take pixel-by-pixel measurements of a silhouette in jpeg or png format for use with the gdi function.
plot_sil Plots a silhouette read by measuresil()
sellipse Estimate area of a superellipse. Assistant function for gdi.
sellipse.coo calculate coordinates for plotting a superellipse for visualizing body cross-sections
vCOM Finds the vertical (y axis, i.e. the axis parallel to the cross-section diameter) position of the center of mass (COM) of the volume. Experimental; only valid for "raw" gdi results with segment volumes approximated as elliptical prisms, or for manually supplied segment COMs. COM is calculated as a weighted mean of all segment COMs, with the segment mass as the weighting factor. Estimates have lower accuracy compared to hCOM, because cross-sectional geometry and variation in density throughout the cross-section is not taken into account.