mirror of
https://github.com/opencv/opencv.git
synced 2024-12-27 11:28:14 +08:00
96 lines
2.4 KiB
C++
96 lines
2.4 KiB
C++
#include "opencv2/core/utility.hpp"
|
|
#include "opencv2/imgproc.hpp"
|
|
#include "opencv2/imgcodecs.hpp"
|
|
#include "opencv2/highgui.hpp"
|
|
|
|
#include <iostream>
|
|
|
|
using namespace cv;
|
|
using namespace std;
|
|
|
|
int _brightness = 100;
|
|
int _contrast = 100;
|
|
|
|
Mat image;
|
|
|
|
/* brightness/contrast callback function */
|
|
static void updateBrightnessContrast( int /*arg*/, void* )
|
|
{
|
|
int histSize = 64;
|
|
int brightness = _brightness - 100;
|
|
int contrast = _contrast - 100;
|
|
|
|
/*
|
|
* The algorithm is by Werner D. Streidt
|
|
* (http://visca.com/ffactory/archives/5-99/msg00021.html)
|
|
*/
|
|
double a, b;
|
|
if( contrast > 0 )
|
|
{
|
|
double delta = 127.*contrast/100;
|
|
a = 255./(255. - delta*2);
|
|
b = a*(brightness - delta);
|
|
}
|
|
else
|
|
{
|
|
double delta = -128.*contrast/100;
|
|
a = (256.-delta*2)/255.;
|
|
b = a*brightness + delta;
|
|
}
|
|
|
|
Mat dst, hist;
|
|
image.convertTo(dst, CV_8U, a, b);
|
|
imshow("image", dst);
|
|
|
|
calcHist(&dst, 1, 0, Mat(), hist, 1, &histSize, 0);
|
|
Mat histImage = Mat::ones(200, 320, CV_8U)*255;
|
|
|
|
normalize(hist, hist, 0, histImage.rows, NORM_MINMAX, CV_32F);
|
|
|
|
histImage = Scalar::all(255);
|
|
int binW = cvRound((double)histImage.cols/histSize);
|
|
|
|
for( int i = 0; i < histSize; i++ )
|
|
rectangle( histImage, Point(i*binW, histImage.rows),
|
|
Point((i+1)*binW, histImage.rows - cvRound(hist.at<float>(i))),
|
|
Scalar::all(0), -1, 8, 0 );
|
|
imshow("histogram", histImage);
|
|
}
|
|
static void help()
|
|
{
|
|
std::cout << "\nThis program demonstrates the use of calcHist() -- histogram creation.\n"
|
|
<< "Usage: \n" << "demhist [image_name -- Defaults to ../data/baboon.jpg]" << std::endl;
|
|
}
|
|
|
|
const char* keys =
|
|
{
|
|
"{@image|../data/baboon.jpg|input image file}"
|
|
};
|
|
|
|
int main( int argc, const char** argv )
|
|
{
|
|
help();
|
|
|
|
CommandLineParser parser(argc, argv, keys);
|
|
string inputImage = parser.get<string>(0);
|
|
|
|
// Load the source image. HighGUI use.
|
|
image = imread( inputImage, 0 );
|
|
if(image.empty())
|
|
{
|
|
std::cerr << "Cannot read image file: " << inputImage << std::endl;
|
|
return -1;
|
|
}
|
|
|
|
namedWindow("image", 0);
|
|
namedWindow("histogram", 0);
|
|
|
|
createTrackbar("brightness", "image", &_brightness, 200, updateBrightnessContrast);
|
|
createTrackbar("contrast", "image", &_contrast, 200, updateBrightnessContrast);
|
|
|
|
updateBrightnessContrast(0, 0);
|
|
waitKey();
|
|
|
|
return 0;
|
|
}
|