《学习OpenCV》练习题第四章第三题b

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

 /*
  *《学习OpenCV》第四章第三题b
  * 完成时间：1:36 3/31 星期日 2013
  */

 /* 矩形框 */
 CvRect rect;

 bool draw = false;   // 标记是否在画

 IplImage* img;
 IplImage * temp;
 IplImage * original;

 bool draw_hist = false;

 IplImage* getHistImage(IplImage* image, CvHistogram* image_hist,
                        CvSize image_size, CvScalar value)
 {
     // 计算直方图
     cvCalcHist( &image, image_hist, , NULL );
     // 新建一幅3通道的图像
     IplImage* dst = cvCreateImage(image_size, IPL_DEPTH_8U,  );

     cvSet( dst, cvScalarAll() );

     float max_value = ;
     cvGetMinMaxHistValue( image_hist, NULL, &max_value, NULL, NULL );
     double bin_width = (double)dst->width/;
     double bin_unith = (double)dst->height/max_value;   // 高度比例

     for(int i = ; i < ; i++)
     {
         // 获得矩形左上角和右下角坐标
         CvPoint p0 = cvPoint( i + bin_width, dst->height );
         CvPoint p1 = cvPoint( (i+) * bin_width,
             dst->height - cvGetReal1D(image_hist->bins, i) *  bin_unith );
         // 画实心矩形
         cvRectangle( dst, p0, p1, value, -, ,  );
     }

     return dst;
 }

 void draw_rect(IplImage* img, CvRect rect)
 {
     cvRectangle( img,
         cvPoint( rect.x, rect.y ),
         cvPoint( rect.x + rect.width, rect.y + rect.height),
         cvScalar( 0x00, 0x00, 0xff) );
     printf("draw\n");

     // 在这里处理直方图
     // 设置感兴趣区域
     cvSetImageROI( img, rect);
     IplImage* src_rect = cvCreateImage (
         cvSize( rect.width, rect.height ),
         img->depth, img->nChannels );
     cvCopy(img, src_rect );
     cvResetImageROI( img );

     IplImage* r_img = cvCreateImage( cvGetSize( src_rect),
         src_rect->depth,  );
     IplImage* g_img = cvCreateImage( cvGetSize( src_rect),
         src_rect->depth,  );
     IplImage* b_img = cvCreateImage( cvGetSize( src_rect),
         src_rect->depth,  );
     IplImage* gray_img = cvCreateImage( cvGetSize( src_rect),
         src_rect->depth,  );

     // 分离RGB分量
     cvSplit( src_rect, r_img, g_img, b_img, NULL);
     cvShowImage( "red", r_img);
     cvShowImage( "green", g_img);
     cvShowImage( "blue", b_img);

     // 灰度转换
     cvCvtColor( src_rect, gray_img, CV_BGR2GRAY);
     int size = ;
     float range[] = {, };
     float* ranges[] = {range};
     // 创建直方图
     CvHistogram * r_hist = cvCreateHist( , &size, CV_HIST_ARRAY, ranges, );
     CvHistogram * g_hist = cvCreateHist( , &size, CV_HIST_ARRAY, ranges, );
     CvHistogram * b_hist = cvCreateHist( , &size, CV_HIST_ARRAY, ranges, );
     CvHistogram * gray_hist = cvCreateHist( , &size, CV_HIST_ARRAY, ranges, );

     // 直方图尺寸
     CvSize image_size = cvSize( , );

     IplImage* r_dst = getHistImage(r_img, r_hist, image_size, cvScalar(0x00, 0x00, 0xff));
     IplImage* g_dst = getHistImage(g_img, g_hist, image_size, cvScalar(0x00, 0xff, 0x00));
     IplImage* b_dst = getHistImage(b_img, b_hist, image_size, cvScalar(0xff, 0x00, 0x00));
     IplImage* gray_dst = getHistImage( gray_img, gray_hist, image_size, cvScalar() );

     // 把四个直方图在一幅图片上显示出来
     IplImage* dst = cvCreateImage( cvSize( image_size.width * , image_size.height * ), ,  );
     cvSetZero( dst );
     // 拷贝红色分量直方图
     CvRect r_rect = cvRect( , , image_size.width, image_size.height);
     cvSetImageROI(dst, r_rect);
     cvCopy( r_dst, dst);
     // 拷贝绿色分量直方图
     CvRect g_rect = cvRect(image_size.width, , image_size.width, image_size.height );
     cvSetImageROI( dst, g_rect);
     cvCopy( g_dst, dst);
     // 蓝色分量
     CvRect b_rect = cvRect(, image_size.height, image_size.width, image_size.height );
     cvSetImageROI(dst, b_rect);
     cvCopy( b_dst, dst );
     // 灰度分量
     CvRect gray_rect = cvRect( image_size.width, image_size.height,
         image_size.width, image_size.height );
     cvSetImageROI( dst, gray_rect);
     cvCopy( gray_dst, dst);

     cvResetImageROI( dst );

     cvShowImage( "src", src_rect);
     cvShowImage( "dst", dst );

     cvWaitKey();

     cvDestroyAllWindows();
     cvReleaseImage( &r_img );
     cvReleaseImage(&g_img);
     cvReleaseImage(&b_img);
     cvReleaseImage(&gray_img);
     cvReleaseImage(&r_dst);
     cvReleaseImage(&g_dst);
     cvReleaseImage(&b_dst);
     cvReleaseImage(&gray_dst);
     cvReleaseImage(&src_rect);
     cvReleaseImage(&dst);
 }

 // 鼠标回调函数
 void my_mouse_callback( int event, int x, int y, int flags, void* param)
 {
     IplImage* image = (IplImage*) param;

     switch( event )
     {
     case CV_EVENT_MOUSEMOVE:
         {
             if(draw)
             {
                 rect.width = x - rect.x;
                 rect.height = y - rect.y;
             }

             draw_hist = false;
         }
         break;
     case CV_EVENT_LBUTTONDOWN:
         {
             draw = true;
             rect = cvRect( x, y, ,  );
             draw_hist = false;
         }
         break;
     case CV_EVENT_LBUTTONUP:
         {
             draw = false;
             draw_hist = true;
             if(rect.width < )
             {
                 rect.x += rect.width;
                 rect.width *= -;
             }
             if(rect.height < )
             {
                 rect.y += rect.height;
                 rect.height *= -;
             }
             // draw
             draw_rect(image, rect);
         }
         break;
         // 在右键按下时清除
     case CV_EVENT_RBUTTONDOWN:
         cvCopyImage(original, img);
         printf("clear.\n");
         break;
     }
 }

 int main()
 {
     img = cvLoadImage( "lena.bmp",  );

     rect = cvRect( -, -, , );

     // 副本
     temp = cvCloneImage( img );
     original = cvCloneImage(img);

     cvNamedWindow("draw rect");
     cvSetMouseCallback("draw rect", my_mouse_callback, (void*)img);

     while()
     {
         cvCopyImage(img, temp);

         if(draw_hist)
         {
             draw_rect( temp , rect );
         }

         cvShowImage( "draw rect", temp);

         if(cvWaitKey() == )
             break;
     }
     cvReleaseImage(&img);
     cvReleaseImage(&temp);
     cvDestroyAllWindows();

     return ;
 }

运行结果：

不足：在源图像上用鼠标选择矩形区域的时候，无法实时地在图像上反映出来。