OpenCV 代码中'System.Runtime.InteropServices.SEHException'未处理的异常

Question

我现在在Windows 7上使用vc++ 2008和OpenCV2.1。我正在尝试facedetect.cpp的例子。当我运行这个程序时，它会弹出一个消息框，上面写着:

An unhandled exception of type 'System.Runtime.InteropServices.SEHException' occurred in Test Console 2.exe
Additional information: External component has thrown an exception.

完整代码如下:

#include "stdafx.h"
#include "cv.h"
#include "highgui.h"
#include <iostream>
#include <cstdio>
using namespace std;
using namespace cv;
void detectAndDraw( Mat& img,
                   CascadeClassifier& cascade, CascadeClassifier& nestedCascade,
                   double scale);
String cascadeName =
"C:/OpenCV2.1/data/haarcascades/haarcascade_frontalface_alt.xml";
String nestedCascadeName =
"C:/OpenCV2.1/data/haarcascades/haarcascade_eye_tree_eyeglasses.xml";
int main( int argc, const char** argv )
{
    CvCapture* capture = 0;
    Mat frame, frameCopy, image;
    const String scaleOpt = "--scale=";
    size_t scaleOptLen = scaleOpt.length();
    const String cascadeOpt = "--cascade=";
    size_t cascadeOptLen = cascadeOpt.length();
    const String nestedCascadeOpt = "--nested-cascade";
    size_t nestedCascadeOptLen = nestedCascadeOpt.length();
    String inputName;
    CascadeClassifier cascade, nestedCascade;
    double scale = 1;
    for( int i = 1; i < argc; i++ )
    {
        if( cascadeOpt.compare( 0, cascadeOptLen, argv[i], cascadeOptLen ) == 0 )
            cascadeName.assign( argv[i] + cascadeOptLen );
        else if( nestedCascadeOpt.compare( 0, nestedCascadeOptLen, argv[i], nestedCascadeOptLen ) == 0 )
        {
            if( argv[i][nestedCascadeOpt.length()] == '=' )
                nestedCascadeName.assign( argv[i] + nestedCascadeOpt.length() + 1 );
            if( !nestedCascade.load( nestedCascadeName ) )
                cerr << "WARNING: Could not load classifier cascade for nested objects" << endl;
        }
        else if( scaleOpt.compare( 0, scaleOptLen, argv[i], scaleOptLen ) == 0 )
        {
            if( !sscanf( argv[i] + scaleOpt.length(), "%lf", &scale ) || scale < 1 )
                scale = 1;
        }
        else if( argv[i][0] == '-' )
        {
            cerr << "WARNING: Unknown option %s" << argv[i] << endl;
        }
        else
            inputName.assign( argv[i] );
    }
    if( !cascade.load( cascadeName ) )
    {
        cerr << "ERROR: Could not load classifier cascade" << endl;
        cerr << "Usage: facedetect [--cascade="<cascade_path>"]n"
            "   [--nested-cascade[="nested_cascade_path"]]n"
            "   [--scale[=<image scale>n"
            "   [filename|camera_index]n" ;
        return -1;
    }
    if( inputName.empty() || (isdigit(inputName.c_str()[0]) && inputName.c_str()[1] == '') )
        capture = cvCaptureFromCAM( inputName.empty() ? 0 : inputName.c_str()[0] - '0' );
    else if( inputName.size() )
    {
        image = imread( inputName, 1 );
        if( image.empty() )
            capture = cvCaptureFromAVI( inputName.c_str() );
    }
    else
        image = imread( "lena.jpg", 1 );
    cvNamedWindow( "result", 1 );
    if( capture )
    {
        for(;;)
        {
            IplImage* iplImg = cvQueryFrame( capture );
            frame = iplImg;
            if( frame.empty() )
                break;
            if( iplImg->origin == IPL_ORIGIN_TL )
                frame.copyTo( frameCopy );
            else
                flip( frame, frameCopy, 0 );
            detectAndDraw( frameCopy, cascade, nestedCascade, scale );
            if( waitKey( 10 ) >= 0 )
                goto _cleanup_;
        }
        waitKey(0);
_cleanup_:
        cvReleaseCapture( &capture );
    }
    else
    {
        if( !image.empty() )
        {
            detectAndDraw( image, cascade, nestedCascade, scale );
            waitKey(0);
        }
        else if( !inputName.empty() )
        {
            /* assume it is a text file containing the
            list of the image filenames to be processed - one per line */
            FILE* f = fopen( inputName.c_str(), "rt" );
            if( f )
            {
                char buf[1000+1];
                while( fgets( buf, 1000, f ) )
                {
                    int len = (int)strlen(buf), c;
                    while( len > 0 && isspace(buf[len-1]) )
                        len--;
                    buf[len] = '';
                    cout << "file " << buf << endl;
                    image = imread( buf, 1 );
                    if( !image.empty() )
                    {
                        detectAndDraw( image, cascade, nestedCascade, scale );
                        c = waitKey(0);
                        if( c == 27 || c == 'q' || c == 'Q' )
                            break;
                    }
                }
                fclose(f);
            }
        }
    }
    cvDestroyWindow("result");
    return 0;
}

异常抛出在这里:

if( !cascade.load( cascadeName ) )
{
    cerr << "ERROR: Could not load classifier cascade" << endl;
    cerr << "Usage: facedetect [--cascade="<cascade_path>"]n"
        "   [--nested-cascade[="nested_cascade_path"]]n"
        "   [--scale[=<image scale>n"
        "   [filename|camera_index]n" ;
    return -1;
}

其余的代码正常工作。当我对上面的部分进行注释后，整个代码的其余部分就可以工作了。相机窗口打开，虽然很明显人脸检测没有触发。

谁能告诉我发生了什么事?

编辑:我在异常期间查看了控制台，发现了以下内容:

OpenCV error:NULL pointer <NULL filename> in unknown function , file ........ocvopencvsrccxcorecxpersistence.cpp, line 2568

这是什么意思?

Answer 1

是否加载了级联来触发人脸检测?它似乎找不到级联路径…

您需要一个级联来使用此人脸检测，并在运行程序时在命令行中最后写入此路径…

Answer 2

cascadecclassifier的load()方法接受一个带有文件名的c++ std::string作为输入

您使用的类型String可能是由Visual Studio某处定义的。我不确定这些类型是否兼容，所以您最好坚持使用#include <string>中的类型。

Answer 3

我认为您应该在调试时将.xml文件的绝对路径放在命令行中。因为当打开这种文件时，使用了标准字符串库的方法，我认为它只是接收绝对路径。