# Histogram3D Vision Data Access functions

This section lists the available 3D Vision Data Access functions that get values from a Histogram3D structure.

Note: Each of the following functions references a Histogram3D structure for the first parameter. Index (zero-based) determines which result of the 3D histogram you want to reference. If you do not specify the index, the index defaults to zero, meaning the function returns the first result. In case Low and High parameters are supported, you can specify the minimum and maximum values of the value range to check by the function.

Function | Description
GetBinSize(Histogram3D) | Returns the size of the histogram's bins.
GetDataValueAtPercentile(Histogram3D, Percentile) | Considering the samples counted in the bins of the histogram, the value corresponding to a given percentile level lies in some bin of the histogram. This function returns the center of that bin, along with a Boolean value indicating whether that value is valid or not.
GetEndValueOfBins(Histogram3D) | Returns the ending value of the bin sequence.
GetFrequency(Histogram3D, [Index]) | Returns the frequency of the specified bin.
GetHead(Histogram3D, [Low], [High]) | Returns the lowest bin-center value across all the bins (and within the value range if specified) whose bin has a non-zero frequency.
GetMax(Histogram3D) | Returns the value of the most prevalent 3D point that occurs in the specified 3D region of interest of the histogram function.
GetMaxInPercentileRange(Histogram3D, [Low], [High]) | Considering the samples counted in the bins of the histogram, the value corresponding to a given percentile level lies in some bin of the histogram. This function returns the maximum value of that bin (or within the specified value range), along with a Boolean value indicating whether that value is valid or not.
GetMean(Histogram3D) | Returns the mean value of the 3D points by summing up the grayscale values for all points in the 3D region of interest of the function, and then dividing by the count of 3D points in the same range.
GetMin(Histogram3D) | Returns the value of the least prevalent 3D point that occurs in the specified 3D region of interest of the histogram function.
GetNumberofBins(Histogram3D) | Returns the number of bins.
GetStandardDeviation(Histogram3D, [Low], [High]) | Returns the standard deviation of the 3D points within the 3D region of interest of the function.
GetStartValueOfBins(Histogram3D) | Returns the starting value of the bin sequence.
GetSumOfFrequencies(Histogram3D, [Low], [High]) | Returns the number of 3D points within the specified threshold range. In the Low Count column of the histogram function output, it returns the number of 3D points below the threshold (returned by the GetThreshold function). In the High Count column of the histogram function output, it returns the number of 3D points above the threshold (returned by the GetThreshold function).
GetTail(Histogram3D, [Low], [High]) | Returns the highest bin-center value across all the bins (and within the value range if specified) whose bin has a non-zero frequency.
GetThreshold(Histogram3D) | Computes an optimum histogram threshold that does a binary segmentation of all the histogram data. That way, GetThreshold specifies a threshold level that maximizes similarity between the 3D region of interest of the histogram function and all possible binary re-quantization.