1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/**
* @file BackProject_Demo1.cpp
* @brief Sample code for backproject function usage
* @author OpenCV team
*/
#include "opencv2/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include <iostream>
using namespace cv;
using namespace std;
/// Global Variables
Mat hue;
int bins = 25;
/// Function Headers
void Hist_and_Backproj(int, void* );
/**
* @function main
*/
int main( int argc, char* argv[] )
{
//! [Read the image]
CommandLineParser parser( argc, argv, "{@input |Back_Projection_Theory0.jpg| input image}" );
samples::addSamplesDataSearchSubDirectory("doc/tutorials/imgproc/histograms/back_projection/images");
Mat src = imread(samples::findFile(parser.get<String>( "@input" )) );
if( src.empty() )
{
cout << "Could not open or find the image!\n" << endl;
cout << "Usage: " << argv[0] << " <Input image>" << endl;
return -1;
}
//! [Read the image]
//! [Transform it to HSV]
Mat hsv;
cvtColor( src, hsv, COLOR_BGR2HSV );
//! [Transform it to HSV]
//! [Use only the Hue value]
hue.create(hsv.size(), hsv.depth());
int ch[] = { 0, 0 };
mixChannels( &hsv, 1, &hue, 1, ch, 1 );
//! [Use only the Hue value]
//! [Create Trackbar to enter the number of bins]
const char* window_image = "Source image";
namedWindow( window_image );
createTrackbar("* Hue bins: ", window_image, &bins, 180, Hist_and_Backproj );
Hist_and_Backproj(0, 0);
//! [Create Trackbar to enter the number of bins]
//! [Show the image]
imshow( window_image, src );
// Wait until user exits the program
waitKey();
//! [Show the image]
return 0;
}
/**
* @function Hist_and_Backproj
* @brief Callback to Trackbar
*/
void Hist_and_Backproj(int, void* )
{
//! [initialize]
int histSize = MAX( bins, 2 );
float hue_range[] = { 0, 180 };
const float* ranges[] = { hue_range };
//! [initialize]
//! [Get the Histogram and normalize it]
Mat hist;
calcHist( &hue, 1, 0, Mat(), hist, 1, &histSize, ranges, true, false );
normalize( hist, hist, 0, 255, NORM_MINMAX, -1, Mat() );
//! [Get the Histogram and normalize it]
//! [Get Backprojection]
Mat backproj;
calcBackProject( &hue, 1, 0, hist, backproj, ranges, 1, true );
//! [Get Backprojection]
//! [Draw the backproj]
imshow( "BackProj", backproj );
//! [Draw the backproj]
//! [Draw the histogram]
int w = 400, h = 400;
int bin_w = cvRound( (double) w / histSize );
Mat histImg = Mat::zeros( h, w, CV_8UC3 );
for (int i = 0; i < bins; i++)
{
rectangle( histImg, Point( i*bin_w, h ), Point( (i+1)*bin_w, h - cvRound( hist.at<float>(i)*h/255.0 ) ),
Scalar( 0, 0, 255 ), FILLED );
}
imshow( "Histogram", histImg );
//! [Draw the histogram]
}
|
