学步园

在这儿介绍一种粗略的普通摄像头深度信息提取方法，很简单，也很实用

“近者大而远者小”，根据目标物体的大小，可以粗略判断出物体的远近

我这里有一个简单的应用，控制图片的大小

视频演示：http://v.youku.com/v_show/id_XMjM2NDk4ODMy.html

截图：

大家可以自己试试看。

也可以下载代码：http://download.csdn.net/source/2979410

或者简单看一下：

int main(int argc,char** argv)<br /> {<br /> CvCapture* capture=cvCreateCameraCapture(-1);<br /> if (!capture){<br /> cout<<"failed to open camera"<<endl;<br /> exit(0);<br /> }<br /> //image for show<br /> IplImage* img=cvLoadImage("Song.jpg");<br /> if (!img){<br /> cout<<"failed to load image"<<endl;<br /> exit(0);<br /> }<br /> CvSize showSize=cvGetSize(img);</p> <p> //processing window size<br /> const CvSize winSizeProcess=cvSize(320,240);<br /> IplImage* imgColor=cvCreateImage(winSizeProcess,8,3);<br /> IplImage* imgGray=cvCreateImage(winSizeProcess,8,1);</p> <p> int threshold=140;<br /> cvNamedWindow("processing");<br /> cvMoveWindow("processing",0,0);<br /> cvCreateTrackbar("threshold","processing",&threshold,200,NULL);</p> <p> int oldImgErea=-1;</p> <p> bool isZooming=false;<br /> IplImage* imgHand;<br /> while (imgHand=cvQueryFrame(capture)){<br /> cvResize(imgHand,imgColor);<br /> cvCvtColor(imgColor,imgColor,CV_RGB2YCrCb);<br /> cvSplit(imgColor,NULL,NULL,imgGray,NULL);<br /> cvThreshold(imgGray,imgGray,threshold,255,CV_THRESH_BINARY);</p> <p> cvShowImage("processing",imgGray);</p> <p> if (isZooming){<br /> cvErode(imgGray,imgGray);<br /> cvDilate(imgGray,imgGray);</p> <p> CvTarget target;<br /> cvFindTarget(imgGray,target);<br /> if (target.erea>HandEreaThreshold){<br /> float scale=1.0f;<br /> if (oldImgErea>0){<br /> scale=(float)target.erea/oldImgErea;<br /> }<br /> oldImgErea=target.erea; </p> <p> showSize.width*=scale;<br /> showSize.height*=scale;<br /> //in defense of limit extreme situation<br /> if (showSize.width<4||showSize.height<4||<br /> showSize.width>2000||showSize.width>2000){<br /> showSize=cvGetSize(img);<br /> }<br /> }<br /> }</p> <p> IplImage* imgResized=cvCreateImage(showSize,8,3);<br /> cvResize(img,imgResized);</p> <p> static int screenWidth=1024;<br /> static int screenHeight=768;<br /> cvMoveWindow("image",(screenWidth-showSize.width)>>1,(screenHeight-showSize.height)>>1);<br /> cvShowImage("image",imgResized);</p> <p> cvReleaseImage(&imgResized);<br /> int keyPressed=cvWaitKey(3);<br /> if(keyPressed==27){<br /> break;<br /> }else if (keyPressed==' '){//start/strop zooming<br /> isZooming=!isZooming;<br /> }<br /> }<br /> cvReleaseImage(&img);<br /> cvReleaseCapture(&capture);<br /> return 0;<br /> }<br />