#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;

#define WINDOW_NAME "【GBR调色板+3滑动条】"

//色彩取值范围0~255，滑动条取值范围0~100。转换比例为2.55。
const int g_nMaxBlueValue = 255;
int g_nBlueValueSlider;
double g_dBlueValue;
double g_dBetaBlueValue;


void on_Trackbar(int, void*)
{
	Mat Image;

	//求出当前Blue值相对于最大值的比例
	g_dBlueValue = (double)g_nBlueValueSlider / g_nMaxBlueValue;
	//则betaBlue值为1减去Blue值
	g_dBetaBlueValue = (1.0 - g_dBlueValue);

	Image = Scalar(g_nBlueValueSlider, g_nBlueValueSlider, g_nBlueValueSlider);

	imshow(WINDOW_NAME, Image);
}

int main()
{
	//设置滑动条初值为255
	g_nBlueValueSlider = 255;

	//创建窗体
	namedWindow(WINDOW_NAME, WINDOW_AUTOSIZE);

	//在创建的窗体中创建一个滑动条控件
	char TrackbarName[300];
	sprintf_s(TrackbarName, "颜色控制 %d", g_nMaxBlueValue);

	createTrackbar(TrackbarName, WINDOW_NAME, &g_nBlueValueSlider, g_nMaxBlueValue, on_Trackbar);

	//结果在回调函数中显示
	on_Trackbar(g_nBlueValueSlider, 0);

	//按任意键退出
	waitKey(0);

	return 0;
}