OpenCV学习笔记之课后习题练习4-1

第四章课后练习1

1.本章完整讲述了基本的输入/输出编程以及OpenCV的数据结构。下面的练习是基于前面的知识做一些应用，为后面大程序的实现提供帮助。
a.创建一个程序实现以下功能：(1)从视频文件中读入数据;(2)将读入数据转换为灰度图;(3)对图像做Canny边缘检测。将三个过程的处理结果显示到不同的窗口中，每个窗口根据其内容合理命名。
b.将所有三个步骤实现显示在一个图像中。
c.在图像的三个不同部分写上合适的文字标签。

a的程序实现如下

 /*ch4_lx4_1_a.cpp
   本程序是learning opencv这本书的课后习题练习
   欢迎提出问题一起讨论*/
 #include "highgui.h"
 #include "cv.h"
 IplImage* doCanny(
     IplImage* img,
     double lowThresh,
     double highThresh,
     double aperture
 ){

     IplImage* out = cvCreateImage(
     cvGetSize(img),
     img->depth,
     );

 cvCanny( img,out,lowThresh,highThresh,aperture);//void cvCanny( const CvArr* image,CvArr* edges,double threshold1,double threshold2, int
 return(out);                                   //aperture_size=3 );
 };
 int main( int argc,char** argv){
 cvNamedWindow( "frame",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "huidu",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "bianyuan",CV_WINDOW_AUTOSIZE);
 CvCapture* capture = cvCreateFileCapture(argv[]);
 IplImage* frame;
 while(){
 frame = cvQueryFrame( capture);
 IplImage* huidu = cvCreateImage( cvSize( frame->width,frame->height ), frame->depth, );
 cvCvtColor(frame, huidu , CV_BGR2GRAY );
 IplImage* bianyuan = doCanny(huidu,,,);
 if( !frame ) break;
 cvShowImage("frame",frame);
 cvShowImage("huidu",huidu);
 cvShowImage("bianyuan",bianyuan);
 char c = cvWaitKey();  //使视频以30帧每秒的速度播放
 if( c==) break;
 }
 cvReleaseCapture( &capture);
 cvDestroyWindow( "frame");
 cvDestroyWindow( "huidu");
 cvDestroyWindow( "bianyuan");
 return ;
 }

b.的程序实现涉及到把三个图像合成到一个图像中显示，具体方法参考一篇博文：https://www.cnblogs.com/CBDoctor/archive/2011/09/19/2180998.html

但这个作者的方法中存在一个问题：第一幅图是显示原图，可是原图变成了灰色，原图的宽度被扩大3倍，只能显示出三分之一，相当于被横向拉伸了3倍。但设置的感兴趣区域是原图的大小，作者并没有给出解答。还需进一步改进。

 /*ch4_lx4_1_b.cpp
   本程序是learning opencv这本书的课后习题练习
   欢迎提出问题一起讨论*/
 #include "highgui.h"
 #include "cv.h"
 IplImage* doCanny(
     IplImage* img,
     double lowThresh,
     double highThresh,
     double aperture
 ){

     IplImage* out = cvCreateImage(
     cvGetSize(img),
     img->depth,
     );

 cvCanny( img,out,lowThresh,highThresh,aperture);//void cvCanny( const CvArr* image,CvArr* edges,double threshold1,double threshold2, int
 return(out);                                   //aperture_size=3 );
 };
 int main( int argc,char** argv){
 cvNamedWindow( "frame",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "huidu",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "bianyuan",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "chuangkou",CV_WINDOW_AUTOSIZE);
 CvCapture* capture = cvCreateFileCapture(argv[]);
 IplImage* frame;
 while(){
 frame = cvQueryFrame( capture);
 IplImage* chuangkou = cvCreateImage(cvSize( frame->width*3.0,frame->height),frame->depth,frame->nChannels);
 cvZero(chuangkou);
 IplImage* huidu = cvCreateImage( cvSize( frame->width,frame->height ), frame->depth, );
 cvCvtColor(frame, huidu , CV_BGR2GRAY );
 IplImage* bianyuan = doCanny(huidu,,,);
 if( !frame ) break;
 //----------------------------------
     //载入原图像到目标图像
     cvSetImageROI(chuangkou, cvRect(, , frame->width, frame->height));
     cvCopy(frame, chuangkou);
      cvResetImageROI(chuangkou);
     //载入灰度图像到目标图像
     cvSetImageROI(chuangkou, cvRect(frame->width, , frame->width, frame->height));
     chuangkou->nChannels =;
     cvCopy(huidu, chuangkou);
     cvResetImageROI(chuangkou);
     //载入边缘检测图像到目标图像
     cvSetImageROI(chuangkou, cvRect((frame->width) *2.0, , frame->width, frame->height));
     chuangkou->nChannels =;
     cvCopy(bianyuan, chuangkou);
     cvResetImageROI(chuangkou);
     //---------------------------------------
 cvShowImage("chuangkou",chuangkou);
 cvShowImage("frame",frame);
 cvShowImage("huidu",huidu);
 cvShowImage("bianyuan",bianyuan);
 char c = cvWaitKey();  //使视频以30帧每秒的速度播放
 if( c==) break;
 }
 cvReleaseCapture( &capture);
 cvDestroyWindow( "frame");
 cvDestroyWindow( "huidu");
 cvDestroyWindow( "bianyuan");
 return ;
 }

c.在图像的三个不同部分写上合适的文字标签。主要是调用cvPutText()函数。

 /*ch4_lx4_1_c.cpp
   添加功能：为三个图像添加文字
   本程序是learning opencv这本书的课后习题练习
   欢迎提出问题一起讨论*/
 #include "highgui.h"
 #include "cv.h"
 IplImage* doCanny(
     IplImage* img,
     double lowThresh,
     double highThresh,
     double aperture
 ){

     IplImage* out = cvCreateImage(
     cvGetSize(img),
     img->depth,
     );

 cvCanny( img,out,lowThresh,highThresh,aperture);//void cvCanny( const CvArr* image,CvArr* edges,double threshold1,double threshold2, int
 return(out);                                   //aperture_size=3 );
 };
 int main( int argc,char** argv){
 cvNamedWindow( "frame",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "huidu",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "bianyuan",CV_WINDOW_AUTOSIZE);
 cvNamedWindow( "chuangkou",CV_WINDOW_AUTOSIZE);
 CvCapture* capture = cvCreateFileCapture(argv[]);
 IplImage* frame;
 while(){
 frame = cvQueryFrame( capture);
 IplImage* chuangkou = cvCreateImage(cvSize( frame->width*3.0,frame->height),frame->depth,frame->nChannels);
 cvZero(chuangkou);
 IplImage* huidu = cvCreateImage( cvSize( frame->width,frame->height ), frame->depth, );
 cvCvtColor(frame, huidu , CV_BGR2GRAY );
 IplImage* bianyuan = doCanny(huidu,,,);
 //为三幅图像添加文字
 CvFont* font;
 cvInitFont(font,CV_FONT_HERSHEY_SIMPLEX,1.0,1.0,0.0,,);
 cvPutText(frame,"liuyutong",cvPoint(,),font,cvScalar(,,));
 cvPutText(huidu,"liuyutong",cvPoint(,),font,cvScalar(,,));
 cvPutText(bianyuan,"liuyutong",cvPoint(,),font,cvScalar(,,));
 if( !frame ) break;
 //----------------------------------
     //载入原图像到目标图像
     cvSetImageROI(chuangkou, cvRect(, , frame->width, frame->height));
     cvCopy(frame, chuangkou);
      cvResetImageROI(chuangkou);
     //载入灰度图像到目标图像
     cvSetImageROI(chuangkou, cvRect(frame->width, , frame->width, frame->height));
     chuangkou->nChannels =;
     cvCopy(huidu, chuangkou);
     cvResetImageROI(chuangkou);
     //载入边缘检测图像到目标图像
     cvSetImageROI(chuangkou, cvRect((frame->width) *2.0, , frame->width, frame->height));
     chuangkou->nChannels =;
     cvCopy(bianyuan, chuangkou);
     cvResetImageROI(chuangkou);
     //---------------------------------------
 cvShowImage("chuangkou",chuangkou);
 cvShowImage("frame",frame);
 cvShowImage("huidu",huidu);
 cvShowImage("bianyuan",bianyuan);
 char c = cvWaitKey();  //使视频以30帧每秒的速度播放
 if( c==) break;
 }
 cvReleaseCapture( &capture);
 cvDestroyWindow( "frame");
 cvDestroyWindow( "huidu");
 cvDestroyWindow( "bianyuan");
 return ;
 }