学习资料：
http://www.opencv.org.cn/opencvdoc/2.3.2/html/doc/tutorials/tutorials.html
包含头文件
core.hpp:包含了基本的定义和库
highgui.hpp:包含了基本的输入输出操作
#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp>
创建一个矩阵对象来存储和载入图像数据
Mat image;
imread函数的第一个参数时载入图像的文件名，第二个参数时图像的格式。格式可以为：
CV_LOAD_IMAGE_UNCHANGED (<0) loads the image as is (including the alpha channel if present)
CV_LOAD_IMAGE_GRAYSCALE ( 0) loads the image as an intensity one
CV_LOAD_IMAGE_COLOR (>0) loads the image in the RGB format
image = imread(argv[1], CV_LOAD_IMAGE_COLOR); // Read the file
创建窗口
CV_WINDOW_AUTOSIZE is the only supported one if you do not use the Qt backend. In this case the window size will take up the size of the image it shows. No resize permitted!
CV_WINDOW_NORMAL on Qt you may use this to allow window resize. The image will resize itself according to the current window size. By using the | operator you also need to specify if you would like the image to keep its aspect ratio (CV_WINDOW_KEEPRATIO) or not (CV_WINDOW_FREERATIO).
namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
显示图片
imshow( "Display window", image ); // Show our image inside it.
等待显示
waitKey(0); // Wait for a keystroke in the window
编译运行
./DisplayImage HappyFish.jpg