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I want to create a histogram within a C# program that uses EMGU. EMGU contains a class called MCvHistogram in it, but I don't know how to use it.

BartoszKP
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White Dwarf
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  • This article shows how to create histogram in RGB http://stackoverflow.com/questions/8204822/how-to-draw-histogram-using-emgucv-and-c-sharp – JiP Jan 14 '14 at 16:05

2 Answers2

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You should use DenseHistogram class if you want to use EmguCV. I'll show you basic usage:

  // Create a grayscale image
  Image<Gray, Byte> img = new Image<Gray, byte>(400, 400);
  // Fill image with random values
  img.SetRandUniform(new MCvScalar(), new MCvScalar(255));
  // Create and initialize histogram
  DenseHistogram hist = new DenseHistogram(256, new RangeF(0.0f, 255.0f));
  // Histogram Computing
  hist.Calculate<Byte>(new Image<Gray, byte>[] { img }, true, null);

There are a lot of other common methods inside DenseHistogram class such as Back Projection

Luca Del Tongo
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  • thanx.. but i already calculate histogram using CvInvoke.cvCalHist(), but i find above method is much easier to use. Can you briefly elaborate difference between McvHistogram and DenseHistogram? – White Dwarf Feb 07 '11 at 04:35
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    DenseHistogram is the managed class that wraps McvHistogram. You can inspect DenseHistogram class and check that it has a property MCvHistogram. My suggestion is to not use cvinvoke when opencv functionality has already been wrapped in proper managed class... – Luca Del Tongo Feb 07 '11 at 10:22
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You can use this code snippet: 

histogramBox.GenerateHistograms(image,bin);               
histogramBox2.Refresh();

It will create a histogram of your picture automatically.

Brian Rasmussen
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HazzA
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