Qt 5.3 under OpenCV 2.4.11 Development (7) single-channel histogram rendering

The main use of the function in the Calchist () function to statistics a histogram, Histogram statistics class header file and source file, the header file code is as follows:

#ifndef histogram1d_h#define histogram1d_h#include <opencv2/core/core.hpp> #include <opencv2/highgui/ Highgui.hpp> #include <opencv2/opencv.hpp>using namespace cv;using namespace Std;class histogram1d{public:    histogram1d ();    Matnd Gethistogram (const Mat &source);    Mat Gethistogramimage (const mat &source);p rivate:    int histsize[1];    Histogram number of items    int channels[1];    Number of channels    float histminmax[2];    Pixel minimum maximum    const float* RANGES[1];//pixel value range}; #endif//Histogram1d_h

The source file code is as follows:

#include "histogram1d.h" histogram1d::histogram1d () {//1d parameter initialization histsize[0] = 256;    Histminmax[0] = 0.0;    HISTMINMAX[1] = 255.0;    Ranges[0] = Histminmax; Channels[0] = 0;}    Matnd Histogram1d::gethistogram (const Mat &source) {matnd Hist;    Calchist (&source, 1, channels, Mat (), Hist, 1, histsize, ranges); return Hist;}  Mat Histogram1d::gethistogramimage (const mat &source) {Matnd hist = Gethistogram (source);//calculation histogram double maxval =    0;    Double minval = 0; Minmaxloc (hist, &minval, &maxval);//Gets the maximum and minimum values Mat histimg (histsize[0], histsize[0], cv_8u, Scalar (255));//    Used to display the histogram image int toppoint = static_cast<int> (0.9*histsize[0]);        for (int i = 0; i < histsize[0]; i + +) {Float Binval = hist.at<float> (i);        int intensity = static_cast<int> (binval*toppoint/maxval); Line (histimg, point (I, histsize[0]), point (I, histsize[0]-intensity), Scalar:    : All (0)); } RETurn histimg;} 

The Main.cpp code snippet is as follows:

#include <QCoreApplication> #include "histogram1d.h" using namespace Cv;using namespace Std;int main () {    Mat src = imread ("Lena.jpg", 0);    HISTOGRAM1D Hg;    Mat histimg = hg.gethistogramimage (src);    Namedwindow ("Histimg", 0);    Imshow ("Histimg", histimg);    Waitkey (0);    return 0;}

Function Description:

void Calchist (const mat* Arrays,        //input source image        int narrays,//            calculation histogram number const int* channels,    // Number of channels Inputarray mask,        //Mask Outputarray hist,       //histogram returned int dims,               //number of dimensions const int* histsize,    // Number of histogram items const float** ranges,   //pixel value range bool Uniform = True,//bool accumulate = false);//

2, Matnd type is a general class, you can manipulate the n-dimensional matrix. He also defines an at method of one-dimensional, two-dimensional and three-dimensional matrices.

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Qt 5.3 under OpenCV 2.4.11 Development (7) single-channel histogram rendering