学步园

通过鼠标和键盘的操作来实现图像的平移，操作方法：用鼠标的话直接拖动图像即可，用键盘的话，使用wsad四个键

来控制图像平移方向，w上，s下，a左，d右。

#include <cv.h>
#include <highgui.h>

IplImage* org = 0;
IplImage* tmp = 0;
IplImage* dst = 0; 
CvRect rect;       //保存图像显示区域

void moveImage()//实现移动
{
	cvCopy(tmp,dst);
	cvSetImageROI(dst,rect);		
	cvCopy(org,dst);
	cvResetImageROI(dst);
	cvShowImage("image",dst);
}

void on_mouse( int event, int x, int y, int flags, void* ustc)
{
	static CvPoint p={-1,-1};
	static int xrect;
	static int yrect;
	if(event==CV_EVENT_LBUTTONDOWN)
	{
		p=cvPoint(x,y);
		xrect=rect.x;
		yrect=rect.y;
	}
	else if(event==CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
	{
		int dx=x-p.x;
		int dy=y-p.y;
	
		if(x>=rect.x && x<=rect.x+rect.width-1 && y>=rect.y && y<=rect.y+rect.height-1)
		{
			rect=cvRect(xrect+dx,yrect+dy,org->width,org->height);
			if(rect.x<0)
			{
				rect.x=0;
			}
			if(rect.y<0)
			{
				rect.y=0;
			}		
			if(rect.x > dst->width - org->width-1)
			{
				rect.x=dst->width-org->width-1;
			}
			if(rect.y > dst->height - org->height-1)
			{
				rect.y=dst->height-org->height-1;
			}
			
			moveImage();
		}	
	}
}

int main()
{
	org=cvLoadImage("test.bmp",1);
	rect=cvRect(0,0,org->width,org->height);
	tmp=cvCreateImage(cvSize(org->width*2,org->height*1.5),org->depth,org->nChannels);
	cvSet(tmp,CV_RGB(192,192,192));
	dst=cvCreateImage(cvSize(org->width*2,org->height*1.5),org->depth,org->nChannels);
	cvSet(dst,CV_RGB(192,192,192));
	cvSetImageROI(dst,cvRect(0,0,org->width,org->height));
	cvCopy(org,dst);
	cvResetImageROI(dst);
	cvNamedWindow("image",1);
	cvShowImage("image",dst);
	cvSetMouseCallback( "image", on_mouse, 0 );
	cvWaitKey(0); 
	
	while (1)
	{
		int key = cvWaitKey (10);
		switch (key)
		{
		case 'w':
			rect=cvRect(rect.x,rect.y-20,org->width,org->height);
			if (rect.y <= 0)
				rect.y = 0;
			moveImage();
			break;

		case 's':
			rect=cvRect(rect.x,rect.y+20,org->width,org->height);
			if (rect.y >= org->height*0.5)
				rect.y = org->height*0.5;
			moveImage();
			break;

		case 'a':
			rect=cvRect(rect.x-20,rect.y,org->width,org->height);
			if (rect.x <= 0)
				rect.x = 0;
			moveImage();
			break;

		case 'd':
			rect=cvRect(rect.x+20,rect.y,org->width,org->height);
			if (rect.x >= org->width)
				rect.x = org->width;
			moveImage();
			break;
		}
	}

	cvDestroyAllWindows();
	cvReleaseImage(&org);
	cvReleaseImage(&tmp);
	cvReleaseImage(&dst);
	return 0;
}