文章目录 HighGUI图像输入，输出，保存；Trackbar鼠标操作鼠标操作 demo:效果
HighGUI
HighGUI为高层GUI图形用户界面模块，包含媒体输入输出，视频捕捉，图像和视频编码解码，图形交互界面的接口等内容。
1、图像输入，输出，保存；
2、滑动条（Trackbar）使用；
3、OpenCV中鼠标操作；
图像输入，输出，保存；
1、Mat类是用于保存图像以及其他矩阵数据的数据结构，默认尺寸为0；
2、imread() :
2、imshow() :
3、imwrite():
4、push_back():
demo:
#include<opencv2/opencv.hpp>#include <vector>using namespace std;using namespace cv;void createAlphaMat(Mat &mat){for (int row = 0; row < mat.rows; row++){for (int col = 0; col < mat.cols; col++){Vec4b &rgba = mat.at<Vec4b>(row, col);rgba[0] = UCHAR_MAX; //0xff;rgba[1] = saturate_cast<uchar>((float(mat.cols - col)) / ((float)mat.cols) * UCHAR_MAX);rgba[2] = saturate_cast<uchar>((float(mat.rows - row)) / ((float)mat.rows) * UCHAR_MAX);rgba[3] = saturate_cast<uchar>(0.5 * (rgba[1] + rgba[2]));}}}int main(){Mat mat(480, 640, CV_8UC4); //创建带alpha通道的Mat；createAlphaMat(mat); //像素值填充vector<int> compression_params;//compression_params.push_back(IMWRITE_PNG_COMPRESSION);compression_params.push_back(9);try {imwrite("透明alpha图.png", mat, compression_params);imshow("PNG图", mat);waitKey(0);}catch (runtime_error & ex){fprintf(stderr, "图像转换成PNG格式发生错误： %sn", ex.what());return -1; }return 0;}
Trackbar
1、Trackbar依附于窗口而存在，必须与回调函数搭配使用：回调函数类型必须为 void XXXX(int ,void*)；
2、getTrackbarPos() : 返回当前轨迹条位置；
鼠标操作
1、指定鼠标操作消息回调函数为 ： SetMouseCallback();
鼠标操作 demo: #include <opencv2/opencv.hpp>using namespace cv;#define WINDOW_NAME "程序窗口"void onMouseHandle(int event, int x, int y, int flags, void* param);void DrawRectangle(Mat & img, Rect box);void ShowHelpText();Rect g_rectangle;bool g_bDrawingBox = false;RNG rng(12345);int main(int argc, char** argv){g_rectangle = Rect(-1, -1, 0, 0);Mat srcImage(600, 800, CV_8UC3), tempImage;namedWindow(WINDOW_NAME);setMouseCallback(WINDOW_NAME, onMouseHandle,(void *) &srcImage);while (1){srcImage.copyTo(tempImage);if (g_bDrawingBox) DrawRectangle(tempImage, g_rectangle);imshow(WINDOW_NAME, tempImage);if (waitKey(10) == 27) //ESC退出{break;}}return 0;}void onMouseHandle(int event, int x, int y, int flags, void* param) {Mat &image = *(cv::Mat *) param;switch (event){case EVENT_MOUSEMOVE:{if (g_bDrawingBox){g_rectangle.width = x - g_rectangle.x;g_rectangle.height = y - g_rectangle.y;}}break;case EVENT_LBUTTONDOWN:{g_bDrawingBox = true;g_rectangle = Rect(x, y, 0, 0); //记录起始点}break;case EVENT_LBUTTONUP:{g_bDrawingBox = false;if (g_rectangle.width < 0){g_rectangle.x += g_rectangle.width;g_rectangle.width *= -1;}if (g_rectangle.height < 0){g_rectangle.y += g_rectangle.y;g_rectangle.height *= -1;}DrawRectangle(image, g_rectangle);}break;default:break;}}void DrawRectangle(Mat & img, Rect box){rectangle(img, box, Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)));//随机颜色}void ShowHelpText(){} 效果