OPENCV学习笔记2_Mat 加载, 显示

enum ImreadModes {
       IMREAD_UNCHANGED     = -1, 
// !< If set, return the loaded image as is (with alpha channel, otherwise it gets cropped).
// 不进行转化，比如保存为了16位的图片，读取出来仍然为16位
       IMREAD_GRAYSCALE     = 0,  
// !< If set, always convert image to the single channel gray scale image.
// 进行转化为灰度图，比如保存为了16位的图片，读取出来为8位，类型为CV_8UC1
       IMREAD_COLOR         = 1,  
// !< If set, always convert image to the 3 channel BGR color image.
// 进行转化为三通道图像
       IMREAD_ANYDEPTH      = 2,  
// 如果图像深度为16位则读出为16位，32位则读出为32位，其余的转化为8位。
       IMREAD_ANYCOLOR      = 4,  
// !< If set, the image is read in any possible color format.
/*
..............
*/
     };
/*
Mat image=imread("test.jpg",CV_LOAD_IMAGE_ANYDEPTH | CV_LOAD_IMAGE_ANYCOLOR);//载入最真实的图像
*/

/*
    The opencv_core module that contains the core functionalities of the library, in particular, the basic data structures and arithmetic functions，包含了程序库的核心功能，特别是基本的数据结构和算法函数；
    The opencv_highgui module that contains the image and video reading and writing functions, along with other user interface functions，包含图像、视频读写函数和部分用户界面函数；
    The opencv_imgproc module that contains the main image processing functions
*/

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>

#include<iostream>
using namespace std;

using namespace cv;

int main( int argc, char** argv ) {

    //Mat image;                         // creates an image of size 0 by 0
    Mat image = cv::imread("test.jpg");  // read an image from file, decode it, and allocate the memory

    if (!image.data)                     // Check for invalid input
    //if(image.empty())
    {
        cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }
    cout << "size: " << image.size().height << " , " << image.size().width << endl;

    namedWindow("My Image", WINDOW_NORMAL);            // Create a window for display

    /*
    Several image transformations in OpenCV can be performed in-place,
    However,we can always create another matrix to hold the output result and that is what we will do:
    */
    Mat result;
    flip(image, result, 1);          // positive for horizontal,0 for vertical,negative for both

    namedWindow("Output Image");     // the result is displayed on another window
                                     // 如不介意窗口大小可变，可直接注释掉上一句,因imshow可以直接创建窗口
    imshow("Output Image", result);  // Show our image inside it

    imshow("My Image", image);       // specify the image to be shown on this special window

    /*
    Since it is a console window that will terminate at the end of the main function, we add an
    extra highgui method to wait for a user key before ending the program:
    */

    waitKey();                            // Wait for a keystroke in the window
    //waitKey(5000);
    //cv::imwrite("output.bmp", result);  // save the processed image on  disk
    return 1;
}