《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, 0, NULL );
    // 新建一幅3通道的图像
    IplImage* dst = cvCreateImage(image_size, IPL_DEPTH_8U, 3 );
    
    cvSet( dst, cvScalarAll(255) );
    
    float max_value = 0;
    cvGetMinMaxHistValue( image_hist, NULL, &max_value, NULL, NULL );
    double bin_width = (double)dst->width/256;
    double bin_unith = (double)dst->height/max_value;   // 高度比例

    for(int i = 0; i < 256; 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+1) * bin_width, 
            dst->height - cvGetReal1D(image_hist->bins, i) *  bin_unith );
        // 画实心矩形
        cvRectangle( dst, p0, p1, value, -1, 8, 0 );
    }

    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
");

    // 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, 1 );
    IplImage* g_img = cvCreateImage( cvGetSize( src_rect),
        src_rect->depth, 1 );
    IplImage* b_img = cvCreateImage( cvGetSize( src_rect),
        src_rect->depth, 1 );
    IplImage* gray_img = cvCreateImage( cvGetSize( src_rect),
        src_rect->depth, 1 );
    
    // 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 = 256;
    float range[] = {0, 255};
    float* ranges[] = {range};
    // 创建直方图
    CvHistogram * r_hist = cvCreateHist( 1, &size, CV_HIST_ARRAY, ranges, 1);
    CvHistogram * g_hist = cvCreateHist( 1, &size, CV_HIST_ARRAY, ranges, 1);
    CvHistogram * b_hist = cvCreateHist( 1, &size, CV_HIST_ARRAY, ranges, 1);
    CvHistogram * gray_hist = cvCreateHist( 1, &size, CV_HIST_ARRAY, ranges, 1);

    // 直方图尺寸
    CvSize image_size = cvSize( 400, 300);
    
    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(0) );

    // 把四个直方图在一幅图片上显示出来
    IplImage* dst = cvCreateImage( cvSize( image_size.width * 2, image_size.height * 2), 8, 3 );
    cvSetZero( dst );
    // 拷贝红色分量直方图
    CvRect r_rect = cvRect( 0, 0, 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, 0, image_size.width, image_size.height );
    cvSetImageROI( dst, g_rect);
    cvCopy( g_dst, dst);
    // 蓝色分量
    CvRect b_rect = cvRect(0, 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(0);

    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, 0, 0 );
            draw_hist = false;
        }
        break;
    case CV_EVENT_LBUTTONUP:
        {
            draw = false;
            draw_hist = true;
            if(rect.width < 0)
            {
                rect.x += rect.width;
                rect.width *= -1;
            }
            if(rect.height < 0)
            {
                rect.y += rect.height;
                rect.height *= -1;
            }
            // draw
            draw_rect(image, rect);
        }
        break;
        // 在右键按下时清除
    case CV_EVENT_RBUTTONDOWN:
        cvCopyImage(original, img);
        printf("clear.
");
        break;
    }
}

int main()
{
    img = cvLoadImage( "lena.bmp", 1 );

    rect = cvRect( -1, -1, 0, 0);
    
    // 副本
    temp = cvCloneImage( img );
    original = cvCloneImage(img);
    
    cvNamedWindow("draw rect");
    cvSetMouseCallback("draw rect", my_mouse_callback, (void*)img);

    while(1)
    {
        cvCopyImage(img, temp);

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

        cvShowImage( "draw rect", temp);

        if(cvWaitKey(15) == 27)
            break;
    }
    cvReleaseImage(&img);
    cvReleaseImage(&temp);
    cvDestroyAllWindows();

    return 0;
}

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。