OpenCV入門，線性混合 使用addWeight函數將兩幅圖像疊加

效果：

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;
#define WINDOW_NAME "線性混合"
const int g_nMaxAlphaValue = 100;//alpha 最大值
int g_nAlphaValueSlider;
double g_dAlphaValue;
double g_dBetaValue;
//存儲圖像的變量
Mat g_srcImage1;
Mat g_srcImage2;
Mat g_dstImage;
void on_Trackbar(int, void*)
{
    //求出當前alpha值相當於最大值的比例
    g_dAlphaValue = (double)g_nAlphaValueSlider / g_nMaxAlphaValue;
    //bata值爲1-alpha值
    g_dBetaValue = (1.0 - g_dAlphaValue);
    //根據alpha和bata值進行混合
    addWeighted(g_srcImage1, g_dAlphaValue, g_srcImage2, g_dBetaValue, 0.0, g_dstImage);
    //顯示效果圖
    imshow(WINDOW_NAME, g_dstImage);
}
int main()
{
    g_srcImage1 = imread("1.jpg");
    g_srcImage2 = imread("2.jpg");
    //設置滑動條初值
    g_nAlphaValueSlider = 70;
    //創建窗體
    namedWindow(WINDOW_NAME, 1);
    //在創建的窗體添加滑動條
    char TrackBarName[50];
    sprintf(TrackBarName, "透明值 %d", g_nMaxAlphaValue);
    createTrackbar(TrackBarName, WINDOW_NAME, &g_nAlphaValueSlider,
        g_nMaxAlphaValue, on_Trackbar);
    //結果在回調函數中顯示
    on_Trackbar(g_nAlphaValueSlider, 0);
    //按任意鍵退出
    waitKey(0);
    return 0;
}