学习OpenCV——全屏显示

在播放视频或需要实时展示时，使用全屏的几率很大，OpenCV现在越来越强大已经支持全屏显示，而不需要在程序中再编写Windows函数，使用起来真是十分方便。

主要依靠Qt New Functions：

setWindowProperty(const string& winname, int prop_id, double prop_value) 

Parameters:

name – Name of the window. prop_id – Window property to edit. The following operation flags are available: CV_WND_PROP_FULLSCREEN Change if the window is fullscreen ( CV_WINDOW_NORMAL or CV_WINDOW_FULLSCREEN ). CV_WND_PROP_AUTOSIZE Change if the window is resizable (CV_WINDOW_NORMAL or CV_WINDOW_AUTOSIZE ). CV_WND_PROP_ASPECTRATIO Change if the aspect ratio of the image is preserved ( CV_WINDOW_FREERATIO or CV_WINDOW_KEEPRATIO ). prop_value – New value of the window property. The following operation flags are available: CV_WINDOW_NORMAL Change the window to normal size or make the window resizable. CV_WINDOW_AUTOSIZE Constrain the size by the displayed image. The window is not resizable. CV_WINDOW_FULLSCREEN Change the window to fullscreen. CV_WINDOW_FREERATIO Make the window resizable without any ratio constraints. CV_WINDOW_KEEPRATIO Make the window resizable, but preserve the proportions of the displayed image.

因此调用全屏，仅仅需要，且不用重新cmake

namedWindow("FullScreen",CV_WINDOW_NORMAL);
setWindowProperty("FullScreen", CV_WND_PROP_FULLSCREEN, CV_WINDOW_FULLSCREEN );

（ Qt New Functions中其他函数：displayOverlay，displayStatusBar，fontQt，addText…… ）

测试程序：

#include 
#include 

using namespace cv;
using namespace std;

int main()
{
	Mat src = imread("E:/Material/Img/Heads/01.jpg",1);
	imshow("src",src);
	namedWindow("FullScreen",CV_WINDOW_NORMAL);
	setWindowProperty("FullScreen", CV_WND_PROP_FULLSCREEN, CV_WINDOW_FULLSCREEN );

	//需要重新编译OpenCV Support Qt
	//displayOverlay("FullScreen","overlay");
	//displayStatusBar("FullScreen","statusBar",10);

	imshow("FullScreen",src);
	waitKey();
}