Class Histogram

Represents a multi-dimensional histogram.

Inheritance

Histogram

Namespace: OpenCV.Net

Assembly: OpenCV.Net.dll

Syntax

public sealed class Histogram : SafeHandleZeroOrMinusOneIsInvalid

Constructors

| Improve this Doc View Source

Histogram(Int32, Int32[], HistogramType, Single[][], Boolean)

Initializes a new instance of the Histogram class with the specified size.

Declaration

public Histogram(int dims, int[] sizes, HistogramType type, float[][] ranges = null, bool uniform = true)

Parameters

Type	Name	Description
Int32	dims	Number of histogram dimensions.
Int32[]	sizes	Array of the histogram dimension sizes.
HistogramType	type	Histogram representation format.
Single[][]	ranges	Array of ranges for the histogram bins.
Boolean	uniform	If true the histogram has evenly spaced bins and for each dimension, `ranges` contains its lower and upper boundaries which are then used to split the dimension into equally sized bins. Otherwise, `ranges` specifies for each dimension the edges of each bin.

Properties

| Improve this Doc View Source

Bins

Gets the multi-dimensional array of histogram data.

Declaration

public Arr Bins { get; }

Property Value

Type	Description
Arr

| Improve this Doc View Source

IsUniform

Gets a value indicating whether the histogram uses evenly spaced bins.

Declaration

public bool IsUniform { get; }

Property Value

Type	Description
Boolean

| Improve this Doc View Source

Type

Gets the type of the histogram representation format.

Declaration

public HistogramType Type { get; }

Property Value

Type	Description
HistogramType

Methods

| Improve this Doc View Source

CalcArrBackProject(Arr[], Arr)

Calculates the back projection.

Declaration

public void CalcArrBackProject(Arr[] images, Arr dst)

Parameters

Type	Name	Description
Arr[]	images	Source images.
Arr	dst	Destination back projection image of the same type as the source `images`.

| Improve this Doc View Source

CalcArrBackProjectPatch(Arr[], Arr, Size, HistogramComparison, Double)

Locates a template within an image by using a histogram comparison.

Declaration

public void CalcArrBackProjectPatch(Arr[] images, Arr dst, Size range, HistogramComparison method, double factor)

Parameters

Type	Name	Description
Arr[]	images	Source images.
Arr	dst	Destination image.
Size	range	Size of the patch slid though the source image.
HistogramComparison	method	The histogram comparison method.
Double	factor	Normalization factor for histograms.

| Improve this Doc View Source

CalcArrHist(Arr[], Boolean, Arr)

Calculates the histogram of image(s).

Declaration

public void CalcArrHist(Arr[] images, bool accumulate = false, Arr mask = null)

Parameters

Type	Name	Description
Arr[]	images	Source images.
Boolean	accumulate	If true, the histogram is not cleared in the beginning. This feature allows the user to compute a single histogram from several images, or to update the histogram online.
Arr	mask	The operation mask, determines what pixels of the source images are counted.

| Improve this Doc View Source

CalcProbDensity(Histogram, Histogram, Double)

Divides one histogram by another and stores the result in this instance.

Declaration

public void CalcProbDensity(Histogram hist1, Histogram hist2, double scale = null)

Parameters

Type	Name	Description
Histogram	hist1	First histogram (the divisor).
Histogram	hist2	Second histogram.
Double	scale	Scale factor.

| Improve this Doc View Source

Clear()

Clears the histogram.

Declaration

public void Clear()

| Improve this Doc View Source

Clone()

Creates a new Histogram that is a copy of the current instance.

Declaration

public Histogram Clone()

Returns

Type	Description
Histogram	A new Histogram that is a copy of this instance.

| Improve this Doc View Source

Compare(Histogram, HistogramComparison)

Compares this histogram with another dense histogram.

Declaration

public double Compare(Histogram other, HistogramComparison method)

Parameters

Type	Name	Description
Histogram	other	The second dense histogram.
HistogramComparison	method	The comparison method to be used.

Returns

Type	Description
Double	The distance between the two histograms.

| Improve this Doc View Source

Copy(out Histogram)

Copies the histogram. The method copies this histogram’s bin values to the destination histogram and sets the same bin value ranges as this instance.

Declaration

public void Copy(out Histogram dst)

Parameters

Type	Name	Description
Histogram	dst	The destination histogram.

| Improve this Doc View Source

GetBinRanges()

Gets the bounds of the histogram bins.

Declaration

public float[][] GetBinRanges()

Returns

Type	Description
Single[][]	The array of ranges for the histogram bins.

| Improve this Doc View Source

GetMinMaxValue(out Single, out Single, Int32[], Int32[])

Finds the minimum and maximum histogram bins.

Declaration

public void GetMinMaxValue(out float minValue, out float maxValue, int[] minIdx = null, int[] maxIdx = null)

Parameters

Type	Name	Description
Single	minValue	The output minimum value of the histogram.
Single	maxValue	The output maximum value of the histogram.
Int32[]	minIdx	The array of coordinates for the minimum.
Int32[]	maxIdx	The array of coordinates for the maximum.

| Improve this Doc View Source

Normalize(Double)

Normalizes the histogram such that the sum of the bins is equal to factor.

Declaration

public void Normalize(double factor)

Parameters

Type	Name	Description
Double	factor	Normalization factor.

| Improve this Doc View Source

QueryValue(Int32)

Queries the value of the histogram bin.

Declaration

public double QueryValue(int idx0)

Parameters

Type	Name	Description
Int32	idx0	The index of the bin.

Returns

Type	Description
Double	The value of the specified bin.

| Improve this Doc View Source

QueryValue(Int32, Int32)

Queries the value of the histogram bin.

Declaration

public double QueryValue(int idx0, int idx1)

Parameters

Type	Name	Description
Int32	idx0	The first index of the bin.
Int32	idx1	The second index of the bin.

Returns

Type	Description
Double	The value of the specified bin.

| Improve this Doc View Source

QueryValue(Int32, Int32, Int32)

Queries the value of the histogram bin.

Declaration

public double QueryValue(int idx0, int idx1, int idx2)

Parameters

Type	Name	Description
Int32	idx0	The first index of the bin.
Int32	idx1	The second index of the bin.
Int32	idx2	The third index of the bin.

Returns

Type	Description
Double	The value of the specified bin.

| Improve this Doc View Source

ReleaseHandle()

Executes the code required to free the native Histogram handle.

Declaration

protected override bool ReleaseHandle()

Returns

Type	Description
Boolean	true if the handle is released successfully; otherwise, in the event of a catastrophic failure, false.

| Improve this Doc View Source

SetBinRanges(Single[][], Boolean)

Sets the bounds of the histogram bins.

Declaration

public void SetBinRanges(float[][] ranges, bool uniform = true)

Parameters

Type	Name	Description
Single[][]	ranges	Array of ranges for the histogram bins.
Boolean	uniform	If true the histogram has evenly spaced bins and for each dimension, `ranges` contains its lower and upper boundaries which are then used to split the dimension into equally sized bins. Otherwise, `ranges` specifies for each dimension the edges of each bin.

| Improve this Doc View Source

Threshold(Double)

Thresholds the histogram by clearing histogram bins that are below the specified threshold.

Declaration

public void Threshold(double threshold)

Parameters

Type	Name	Description
Double	threshold	Threshold level.