Question

我正在尝试在网络摄像头的实时视频上实现opencv的canny边缘检测。但是，我收到了这个错误：

OpenCV错误：未报告的格式或格式组合＆lt;＆gt;在未知功能，文件........ \ ocv \ opencv \ src \ cv \ cvcanny.cpp，第66行

我想这是一个格式问题。我可以将3通道8位RGB图像转换为1通道灰度图像帧，然后对结果执行边缘检测。但是，我也无法在图像上实现rgb2grayscale转换; ＆LT;此转换代码的通道数不正确＆gt;

以下是我在VS2008中实现的代码。有关如何解决此错误的任何想法？

#pragma once

#include <stdio.h>
#include <tchar.h>
#include <iostream>
#include <conio.h>
#include <iomanip>
#include <cv.h>
#include <cvaux.h>
#include <cxcore.h>
#include <highgui.h>
#include <math.h>
#include <string.h>
#include <cxtypes.h>


using namespace std;
using namespace cv;

int main(int, char**)
{

    cvNamedWindow("Edges", CV_WINDOW_AUTOSIZE); 
CvCapture* capture = cvCaptureFromCAM(0);

IplImage* frame;
    while(1) {
        frame = cvQueryFrame( capture );


        int depth_img =frame->depth;
        int height_img =frame->height;
        int width_img =frame->width;
        int size_img =frame->imageSize;
        int nchan_img =frame->nChannels;
        int nsize_img =frame->nSize;

        cout << setw(15) << "depth" <<  depth_img << endl;
        cout << setw(15) << "height" <<  height_img << endl;
        cout << setw(15) << "width" <<  width_img << endl;
        cout << setw(15) << "size" <<  size_img << endl;
        cout << setw(15) << "nchan" <<  nchan_img << endl;
        cout << setw(15) << "nsize" <<  nsize_img << endl;


        IplImage* out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 3 );
        cvSmooth( frame, out, CV_GAUSSIAN, 11, 11 );
        cvCvtColor(out ,out, CV_RGB2GRAY);
        cvCanny( out, out, 10, 10, 3 );

        if( !frame ) break;
        cvShowImage( "Edge", out );
        char c = cvWaitKey(33);
        if( c == 27 ) break;
    }
    cvReleaseCapture( &capture );
    cvDestroyWindow( "Edge" );
    return 0;
}

Answer 1

问题是你每次传递一个3通道图像

IplImage* out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 3 );

创建其他两个单通道图像并使用它们：

IplImage* gray_out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 1 );
IplImage* canny_out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 1 );

并将其用于：

cvSmooth( frame, out, CV_GAUSSIAN, 11, 11 );
cvCvtColor(out , gray_out, CV_RGB2GRAY);
cvCanny( gray_out, canny_out, 10, 10, 3 );

if( !frame ) break;
cvShowImage( "Edge", canny_out );

这对我有用：

#include <stdio.h>
#include <iostream>
#include <iomanip>
#include <cv.h>
#include <cvaux.h>
#include <cxcore.h>
#include <highgui.h>
#include <math.h>
#include <string.h>


using namespace std;
using namespace cv;

int main(int, char**)
{

    cvNamedWindow("Edges", CV_WINDOW_AUTOSIZE); 
CvCapture* capture = cvCaptureFromCAM(0);

IplImage* frame;
    while(1) {
        frame = cvQueryFrame( capture );

        int depth_img =frame->depth;
        int height_img =frame->height;
        int width_img =frame->width;
        int size_img =frame->imageSize;
        int nchan_img =frame->nChannels;
        int nsize_img =frame->nSize;

        cout << setw(15) << "depth" <<  depth_img << endl;
        cout << setw(15) << "height" <<  height_img << endl;
        cout << setw(15) << "width" <<  width_img << endl;
        cout << setw(15) << "size" <<  size_img << endl;
        cout << setw(15) << "nchan" <<  nchan_img << endl;
        cout << setw(15) << "nsize" <<  nsize_img << endl;


        IplImage* out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 3 );
        IplImage* gray_out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 1 );
        IplImage* canny_out = cvCreateImage( cvGetSize(frame), IPL_DEPTH_8U, 1 );
        cvSmooth( frame, out, CV_GAUSSIAN, 11, 11 );
        cvCvtColor(out , gray_out, CV_RGB2GRAY);
        cvCanny( gray_out, canny_out, 10, 10, 3 );

        if( !frame ) break;
        cvShowImage( "Edge", canny_out );
        char c = cvWaitKey(33);
        if( c == 27 ) break;
    }
    cvReleaseCapture( &capture );
    cvDestroyWindow( "Edge" );
    return 0;
}

Answer 2

你正在使用OpenCV 2.x吗？这里的代码也有效，但在以下几点之前：

请记住，OpenCV与BGR一起使用，因此在转换时，请使用CV_BGR2GRAY
小心Canny中的阈值，它们应该是不同的，比例为2或3（推荐）。可能会尝试100-200 ......
尽量避免在每个循环中打印，这会使代码慢一点
对于过滤器，尽量不要使用大窗口。最大尺寸3 0r 5通常很好（取决于您的应用）。可能不需要11号。

好的，这里是代码：

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>
#include <stdlib.h>

using namespace std;
using namespace cv;

int main(int, char**)
{
    namedWindow( "Edges", CV_WINDOW_NORMAL ); 
    CvCapture* capture = cvCaptureFromCAM(-1);

    cv::Mat frame; cv::Mat out; cv::Mat out2;

    while(1) {
        frame = cvQueryFrame( capture );

        GaussianBlur( frame, out, Size(5, 5), 0, 0 );
        cvtColor( out ,out2, CV_BGR2GRAY ); // produces out2, a one-channel image (CV_8UC1)
       Canny( out2, out2, 100, 200, 3 ); // the result goes to out2 again,but since it is still one channel it is fine

        if( !frame.data ) break;
        imshow( "Edges", out2 );

        char c = cvWaitKey(33);
        if( c == 'c' ) break;
    }
    return 0;
}

顺便说一下，你可以考虑使用cv :: Mat。它比IplImage更灵活，实际上（不再有Release Image ......）

Answer 3

#include <opencv2/opencv.hpp>
#include <iostream>
using namespace cv;
using namespace std;



int main()
{
    Mat img;
    VideoCapture cap(0);

    while (true)
    {
        cap >> img;

        Mat edges;
        cvtColor(img, edges, CV_BGR2GRAY);

        Canny(edges, edges, 30, 60);

        imshow("window label", edges);
        waitKey(1);
    }

    return 0;
}

这是我使用canny功能拍摄的方式。

实时视频上的OpenCV Canny Edge

3 个答案: