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https://gitcode.com/gh_mirrors/es/esp32-opencv.git
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90 lines
3.0 KiB
C++
90 lines
3.0 KiB
C++
/**
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* @function calcHist_Demo.cpp
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* @brief Demo code to use the function calcHist
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* @author
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*/
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#include "opencv2/highgui.hpp"
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#include "opencv2/imgcodecs.hpp"
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#include "opencv2/imgproc.hpp"
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#include <iostream>
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using namespace std;
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using namespace cv;
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/**
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* @function main
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*/
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int main(int argc, char** argv)
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{
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//! [Load image]
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CommandLineParser parser( argc, argv, "{@input | lena.jpg | input image}" );
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Mat src = imread( samples::findFile( parser.get<String>( "@input" ) ), IMREAD_COLOR );
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if( src.empty() )
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{
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return EXIT_FAILURE;
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}
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//! [Load image]
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//! [Separate the image in 3 places ( B, G and R )]
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vector<Mat> bgr_planes;
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split( src, bgr_planes );
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//! [Separate the image in 3 places ( B, G and R )]
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//! [Establish the number of bins]
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int histSize = 256;
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//! [Establish the number of bins]
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//! [Set the ranges ( for B,G,R) )]
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float range[] = { 0, 256 }; //the upper boundary is exclusive
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const float* histRange = { range };
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//! [Set the ranges ( for B,G,R) )]
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//! [Set histogram param]
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bool uniform = true, accumulate = false;
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//! [Set histogram param]
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//! [Compute the histograms]
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Mat b_hist, g_hist, r_hist;
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calcHist( &bgr_planes[0], 1, 0, Mat(), b_hist, 1, &histSize, &histRange, uniform, accumulate );
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calcHist( &bgr_planes[1], 1, 0, Mat(), g_hist, 1, &histSize, &histRange, uniform, accumulate );
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calcHist( &bgr_planes[2], 1, 0, Mat(), r_hist, 1, &histSize, &histRange, uniform, accumulate );
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//! [Compute the histograms]
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//! [Draw the histograms for B, G and R]
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int hist_w = 512, hist_h = 400;
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int bin_w = cvRound( (double) hist_w/histSize );
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Mat histImage( hist_h, hist_w, CV_8UC3, Scalar( 0,0,0) );
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//! [Draw the histograms for B, G and R]
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//! [Normalize the result to ( 0, histImage.rows )]
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normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
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normalize(g_hist, g_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
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normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
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//! [Normalize the result to ( 0, histImage.rows )]
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//! [Draw for each channel]
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for( int i = 1; i < histSize; i++ )
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{
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line( histImage, Point( bin_w*(i-1), hist_h - cvRound(b_hist.at<float>(i-1)) ),
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Point( bin_w*(i), hist_h - cvRound(b_hist.at<float>(i)) ),
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Scalar( 255, 0, 0), 2, 8, 0 );
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line( histImage, Point( bin_w*(i-1), hist_h - cvRound(g_hist.at<float>(i-1)) ),
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Point( bin_w*(i), hist_h - cvRound(g_hist.at<float>(i)) ),
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Scalar( 0, 255, 0), 2, 8, 0 );
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line( histImage, Point( bin_w*(i-1), hist_h - cvRound(r_hist.at<float>(i-1)) ),
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Point( bin_w*(i), hist_h - cvRound(r_hist.at<float>(i)) ),
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Scalar( 0, 0, 255), 2, 8, 0 );
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}
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//! [Draw for each channel]
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//! [Display]
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imshow("Source image", src );
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imshow("calcHist Demo", histImage );
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waitKey();
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//! [Display]
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return EXIT_SUCCESS;
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}
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