ImageGear for .NET
TabulateHistogram Method
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ImageGear21.Core Assembly > ImageGear.Processing Namespace > ImGearRasterProcessing Class : TabulateHistogram Method

page: Page for which to tabulate histogram.

histogram: Two dimensional array that is filled with histogram data. It must be allocated prior to calling the method. First dimension corresponds to channel number, second dimension corresponds to histogram bin number.

channels: Specifies image channels for which histogram shall be tabulated.

Tabulates histograms for all image channels.

Syntax

Visual Basic

Managed Extensions for C++

C++/CLI

'Declaration
 
Public Shared Sub TabulateHistogram( _
   ByVal page As ImGearRasterPage, _
   ByVal histogram(,) As Integer, _
   ByVal channels As ImGearChannelRange _
)

'Usage
 
Dim page As ImGearRasterPage
Dim histogram() As Integer
Dim channels As ImGearChannelRange
 
ImGearRasterProcessing.TabulateHistogram(page, histogram, channels)

public static void TabulateHistogram( 
   ImGearRasterPage page,
   int[,] histogram,
   ImGearChannelRange channels
)

public: static void TabulateHistogram( 
   ImGearRasterPage* page,
   int[,]* histogram,
   ImGearChannelRange channels
)

public:
static void TabulateHistogram( 
   ImGearRasterPage^ page,
   array<int>^ histogram,
   ImGearChannelRange channels
)

Parameters

page: Page for which to tabulate histogram.
histogram: Two dimensional array that is filled with histogram data. It must be allocated prior to calling the method. First dimension corresponds to channel number, second dimension corresponds to histogram bin number.
channels: Specifies image channels for which histogram shall be tabulated.

Remarks

This method tabulates histograms for all image channels.

This method supports images with channel depths ranging from 2 to 16.

Example

C#	Copy Code
// Calculate image histogram. // Channel range to calculate. ImGearChannelRange igChannelRange = new ImGearChannelRange(0, igRasterPage.DIB.ChannelCount); // Integer array to hold histogram data int[,] histogramData = new int[igRasterPage.DIB.ChannelCount,(int)Math.Pow(2,igRasterPage.DIB.BitsPerChannel)]; //Tabulate the histogram data. ImGearRasterProcessing.TabulateHistogram(igRasterPage, histogramData, igChannelRange); // Show a piece of the data. MessageBox.Show(histogramData[0,0] + " pixels had the value 0 for the first channel.", "Histogram Data");

Copy Code

// Calculate image histogram.

// Channel range to calculate.
ImGearChannelRange igChannelRange = new ImGearChannelRange(0, igRasterPage.DIB.ChannelCount);
// Integer array to hold histogram data
int[,] histogramData = new int[igRasterPage.DIB.ChannelCount,(int)Math.Pow(2,igRasterPage.DIB.BitsPerChannel)];

//Tabulate the histogram data.
ImGearRasterProcessing.TabulateHistogram(igRasterPage, histogramData, igChannelRange);

// Show a piece of the data.
MessageBox.Show(histogramData[0,0] + " pixels had the value 0 for the first channel.", "Histogram Data");

Visual Basic	Copy Code
' Calculate image histogram. ' Channel range to calculate. Dim igChannelRange As New ImGearChannelRange(0, igRasterPage.DIB.ChannelCount) ' Integer array to hold histogram data Dim numberOfValues As Integer numberOfValues = CInt(Math.Pow(2, igRasterPage.DIB.BitsPerChannel)) Dim histogramData As Integer(,) = New Integer(igRasterPage.DIB.ChannelCount - 1, numberOfValues - 1) {} 'Tabulate the histogram data. ImGearRasterProcessing.TabulateHistogram(igRasterPage, histogramData, igChannelRange) ' Show a piece of the data. MessageBox.Show(histogramData(0, 0).ToString() + " pixels had the value 0 for the first channel.", "Histogram Data")