Question

大家好，我有一些问题从视频中提取清晰的轮廓。目前轮廓看起来像一团糟。我遵循的步骤是：

将视频作为输入
将其转换为灰度
将其阈值设为二进制
使用cvFindContours（）
遍历轮廓并使用cvDrawContours

代码如下：

IplImage *inFrame;
IplImage *outFrame = cvCreateImage(cvSize(width,height),IPL_DEPTH_8U,3);
CvScalar inPixel, outPixel;

//J.M ================================================//
CvMemStorage *mem = cvCreateMemStorage(0), *polymem = cvCreateMemStorage(0);
CvSeq *contours = NULL, *ptr = NULL, *poly = NULL, *convex_hull = NULL;
IplImage *cc_color = cvCreateImage(cvGetSize(outFrame), IPL_DEPTH_8U, 3);
CvScalar externalColor = CV_RGB( 255, 252, 0 );
CvScalar holeColor = CV_RGB( 255, 0, 0 );
CvFont font;
int contourNum = 0;
//=========================================================================//

frame_no = 0;
processingVideo = true;
this->GetDlgItem(IDC_STOP)->EnableWindow(true);

CString title = "Video Processing";
cvNamedWindow(title, CV_WINDOW_AUTOSIZE);

CvVideoWriter *writer = cvCreateVideoWriter(pathOutVideo,CV_FOURCC('I', 'Y', 'U', 'V'),video->getFPS(),cvSize(width,height),1);

// variables for counting time
clock_t begin, current;
long int secs, rem_secs, t1, t2;
begin = clock();

while(inFrame=cvQueryFrame(video->getCapture()))
{
    if(!processingVideo)
        break;

    // close opencv window?
    if(cvGetWindowHandle(title)==NULL)
        break;

    //==============================================================================================//

    /*Create gray-scale image*/
    IplImage *im_gray = cvCreateImage(cvGetSize(outFrame), IPL_DEPTH_8U, 1);
    cvCvtColor(inFrame, im_gray, CV_RGB2GRAY);
    outFrame = im_gray;

    /*Convert gray-scale image to binary*/
    IplImage* img_bw = cvCreateImage(cvGetSize(im_gray), IPL_DEPTH_8U, 1); 
    cvThreshold(im_gray, img_bw, 128, 255, CV_THRESH_BINARY | CV_THRESH_OTSU);
    outFrame = img_bw;

    contourNum = cvFindContours(outFrame, mem, &contours, sizeof(CvContour), CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0));

    /* I have tried using convex_hull but with no success
    convex_hull = cvConvexHull2( contours, polymem, CV_CLOCKWISE, 2 ); 
    poly = cvApproxPoly(convex_hull, sizeof(CvContour), polymem, CV_POLY_APPROX_DP, cvContourPerimeter(contours)*0.02, 0); 
    float size = fabs(cvContourArea( poly, CV_WHOLE_SEQ )); */

    for (ptr = contours; ptr != NULL; ptr = ptr->h_next) {
            cvDrawContours(cc_color, ptr, externalColor, holeColor, -1, CV_FILLED, 8, cvPoint(0,0));
    }

    outFrame = cc_color;
    //==============================================================================================//

我还提供了各种步骤结果的图像实例。

源视频输入（http://imageshack.us/photo/my-images/823/sourcevideo.jpg/）
灰度视频（http://imageshack.us/photo/my-images/23/grayscalei.jpg/）
二进制视频（http://imageshack.us/photo/my-images/684/binaryi.jpg/）
最终轮廓输出（http://imageshack.us/photo/my-images/35/finaloutput.jpg/）

如果您需要更多信息，请说出来:) 我想知道你们中的任何人是否可以给我一些建议，如何继续或我做错了什么。谢谢!!!

Answer 1

您的Step: 3 Threshold it to binary 需要一些改进。我想你想要在一个语义上有意义的对象周围绘制轮廓。在这种情况下，由于相同的灰度值是许多对象的一部分 - 结果图像不是对象边界的精确度量。

您需要尝试的是分段方法 - 例如分水岭算法或区域增长算法。 OpenCV本身有很多实现。

如何使用openCV库在视频中提取清晰的轮廓

1 个答案: