Consult, the use of OPENCV opened the camera image magnification, but cannot be magnified beyond the screen resolution,
Enlarge how to increase the window size to the desktop height after all not a line, what to do.

 
//ConsoleApplication1. CPP: defines the entry point of the console application, 

//

# include "stdafx. H" 
#include  
#include  
H # include "Windows." 
# include "dshow. H" 
#include  

# pragma comment (lib, "strmiids. Lib") 
# pragma comment (lib, "quartz. Lib") 

using namespace cv; 
using namespace std; 

Int main () 
{
Int capid0=0; 


VideoCapture cap0; 
cout <"Capid=" & lt; Cap0. Open (capid0); 
Mat frame0; 
NamedWindow (" ImageShow_PIC ", 0);//create the OpenCV window 
ResizeWindow (" ImageShow_PIC ", the Size (1280, 720)); 
While (waitKey (30).=27)//esc 
{
Cap0 & gt;> Frame0; 
Imshow (" ImageShow_PIC frame0); 
If (waitKey (30)==32)//space 
{
Yyy +=10; 
ResizeWindow (" ImageShow_PIC ", the Size (1280, yyy)); 
} 
} 
return 0; 
}