1 /**
2 * @file BasicLinearTransforms.cpp
3 * @brief Simple program to change contrast and brightness
4 * @author OpenCV team
5 */
6
7 #include "opencv2/imgcodecs.hpp"
8 #include "opencv2/highgui/highgui.hpp"
9 #include <iostream>
10
11 using namespace cv;
12
13 double alpha; /**< Simple contrast control */
14 int beta; /**< Simple brightness control */
15
16 /**
17 * @function main
18 * @brief Main function
19 */
main(int,char ** argv)20 int main( int, char** argv )
21 {
22 /// Read image given by user
23 Mat image = imread( argv[1] );
24 Mat new_image = Mat::zeros( image.size(), image.type() );
25
26 /// Initialize values
27 std::cout<<" Basic Linear Transforms "<<std::endl;
28 std::cout<<"-------------------------"<<std::endl;
29 std::cout<<"* Enter the alpha value [1.0-3.0]: ";std::cin>>alpha;
30 std::cout<<"* Enter the beta value [0-100]: "; std::cin>>beta;
31
32
33 /// Do the operation new_image(i,j) = alpha*image(i,j) + beta
34 /// Instead of these 'for' loops we could have used simply:
35 /// image.convertTo(new_image, -1, alpha, beta);
36 /// but we wanted to show you how to access the pixels :)
37 for( int y = 0; y < image.rows; y++ )
38 { for( int x = 0; x < image.cols; x++ )
39 { for( int c = 0; c < 3; c++ )
40 {
41 new_image.at<Vec3b>(y,x)[c] = saturate_cast<uchar>( alpha*( image.at<Vec3b>(y,x)[c] ) + beta );
42 }
43 }
44 }
45
46 /// Create Windows
47 namedWindow("Original Image", 1);
48 namedWindow("New Image", 1);
49
50 /// Show stuff
51 imshow("Original Image", image);
52 imshow("New Image", new_image);
53
54
55 /// Wait until user press some key
56 waitKey();
57 return 0;
58 }
59