CODEWITHSUNDEEP
c++xmlopencv
rocket_brain
rocket_brain

Reputation: 89

XML Parsing Error while loading HarrCascade into CascadeClassifier

I am new to openCV and copied some basic eye/face tracking code from example code. I receive a parsing error on line 20 - "face_cascade.load(...)". 

String face_cascade_name = "C:/Users/$Username$/Downloads/haarcascade_frontalface_alt.xml";

if (!face_cascade.load( face_cascade_name ) )
    {
        cout << "--(!)Error loading eyes cascade\n";
        return -1;
    };

When I run it (in release mode), I get an "unhandled exception" and break. In debug mode, I also get an XML parsing error to the console (see below).

When debugging, I found everything runs as expected ONLY IF I use "haarcascade_eye_tree_eyeglasses.xml" as my CascadeClassifier.

String face_cascade_name = "C:/Users/$Username$/Downloads/haarcascade_eye_tree_eyeglasses.xml"

I have tried re-downloading the HaarCascades multiple times from openCV's github (I don't see any other complaints about bad XML files). I have tried to load multiple different XML files, but all throw the same error, other than the "haarcascade_eye_tree_eyeglasses.xml". I can't find this issue anywhere else I've looked online. I've tried re-building the openCV library, and even tried pasting the other classifier XML data into the header of "haarcascade_eye_tree_eyeglasses.xml" and don't know what to try next.

Any ideas why only 1 HaarCascade XML file is loading correctly?

Visual Studio Windowed Error

Unhandled exception at 0x00007FFC5E3F9129 in testCV.exe: Microsoft C++ exception: cv::Exception at memory location 0x000000883396DF90.

Debug Console Error

OpenCV(4.1.0-dev) Error: Parsing error (cv::XMLParser::parse) in C:\Users\$Username$\source\repos\testCV\haarcascade_frontalface_alt.xml(1): Valid XML should start with '<?xml ...?>', file C:\Users\$Username$\Downloads\opencv-master\modules\core\src\persistence_xml.cpp, line 786

persistance_xml.cpp line 774-786:

    bool parse(char* ptr)
    {
        CV_Assert( fs != 0 );

        std::string key, key2, type_name;
        int tag_type = 0;
        bool ok = false;

        // CV_XML_INSIDE_TAG is used to prohibit leading comments
        ptr = skipSpaces( ptr, CV_XML_INSIDE_TAG );

        if( memcmp( ptr, "<?xml", 5 ) != 0 )  // FIXIT ptr[1..] - out of bounds read without check
            CV_PARSE_ERROR_CPP( "Valid XML should start with \'<?xml ...?>\'" );

I am using Visual Studio 2017, OpenCV 4.1.0, Win10.

Upvotes: 0

Views: 5339

Answers (3)

WaterAndFlowe
WaterAndFlowe

Reputation: 1

Here ,I finally find the true answer.

You need to change xml files to UTF-8. Usually ,We download the file is UTF-8 With Bom.

You Can Change the File Code Using VsCode APP.(Please Google it)

Upvotes: 0

Varun Tripathi
Varun Tripathi

Reputation: 151

Clone "OpenCV" repository from github (https://github.com/opencv/opencv/tree/master) on your local machine. "Dont" copy content .Copy paste file directly from cloned location to your visual studio. It would work.

Upvotes: 0

gpro
gpro

Reputation: 592

I had this issue when copy/pasted the content of those xml files from GitHub to a local file. After cloning the repo locally, and coping the xml files to the desired place the parsing issue disappeared.

Upvotes: 1

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