OpenCV 为程序界面添加滑动条

 #include <cv.h>
 #include <highgui.h>

 using namespace cv;

 /// 全局变量的声明与初始化
 const int alpha_slider_max = ;
 int alpha_slider;
 double alpha;
 double beta;

 /// 声明存储图像的变量
 Mat src1;
 Mat src2;
 Mat dst;

 /**
  * @function on_trackbar
  * @定义响应滑动条的回调函数
  */
 void on_trackbar( int, void* )
 {
  alpha = (double) alpha_slider/alpha_slider_max ;
  beta = ( 1.0 - alpha );

  addWeighted( src1, alpha, src2, beta, 0.0, dst);

  imshow( "Linear Blend", dst );
 }

 int main( int argc, char** argv )
 {
  /// 加载图像 (两图像的大小与类型要相同)
  src1 = imread("../../images/LinuxLogo.jpg");
  src2 = imread("../../images/WindowsLogo.jpg");

  if( !src1.data ) { printf("Error loading src1 \n"); return -; }
  if( !src2.data ) { printf("Error loading src2 \n"); return -; }

  /// 初始化为零
  alpha_slider = ;

  /// 创建窗体
  namedWindow("Linear Blend", );

  /// 在创建的窗体中创建一个滑动条控件
  char TrackbarName[];
  sprintf( TrackbarName, "Alpha x %d", alpha_slider_max );

  createTrackbar( TrackbarName, "Linear Blend", &alpha_slider, alpha_slider_max, on_trackbar );

  /// 结果在回调函数中显示
  on_trackbar( alpha_slider,  );

  /// 按任意键退出
  waitKey();
  return ;
 }