您好，我正在做一个使用OpenCV来检测矩形/正方形的android应用程序，以检测它们/我正在使用来自squares.cpp的函数(稍作修改)。找到的每个正方形的点都存储在vector> squares中，然后将其传递给选择最大正方形的函数并将其存储在 vector theBiggestSq中。问题在于裁剪功能，我将在其下面粘贴代码(我也会将链接发布到youtube上，以显示问题)。如果实际的正方形距离相机足够远，则可以正常工作，但是如果我将其关闭一点，它将挂起。我将通过LogCat发布问题的打印屏幕，并打印出一些点(从BiggestSq vector 中获取的边界点，也许会有助于找到解决方案)。

void cutAndSave(vector<Point> theBiggestSq, Mat image){
    RotatedRect box = minAreaRect(Mat(theBiggestSq));
    // Draw bounding box in the original image (debug purposes)
    //cv::Point2f vertices[4];
    //box.points(vertices);
    //for (int i = 0; i < 4; ++i)
    //{
    //cv::line(img, vertices[i], vertices[(i + 1) % 4], cv::Scalar(0, 255, 0), 1, CV_AA);
    //}
    //cv::imshow("box", img);
    //cv::imwrite("box.png", img);
    // Set Region of Interest to the area defined by the box
    Rect roi;
    roi.x = box.center.x - (box.size.width / 2);
    roi.y = box.center.y - (box.size.height / 2);
    roi.width = box.size.width;
    roi.height = box.size.height;
    // Crop the original image to the defined ROI

    //bmp=Bitmap.createBitmap(box.size.width / 2, box.size.height / 2, Bitmap.Config.ARGB_8888);
    Mat crop = image(roi);
    //Mat crop = image(Rect(roi.x, roi.y, roi.width, roi.height)).clone();
    //Utils.matToBitmap(crop*.clone()* ,bmp);
    imwrite("/sdcard/OpenCVTest/1.png", bmp);
    imshow("crop", crop);

}

//draw//
    for( size_t i = 0; i < squares.size(); i++ )
    {
        const Point* p = &squares[i][0];
        int n = (int)squares[i].size();
        polylines(mBgra, &p, &n, 1, true, Scalar(255,255,0), 5, 10);
        //Rect rect = boundingRect(cv::Mat(squares[i]));
        //rectangle(mBgra, rect.tl(), rect.br(), cv::Scalar(0,255,0), 2, 8, 0);

    }

最佳答案

该错误基本上可以告诉您原因-您的投资返回率超出了图像尺寸。这意味着当您从Rect roi中提取RotatedRect box时，x或y小于零，或者宽度/高度将尺寸推到图像之外。您应该使用类似的方法进行检查

// Propose rectangle from data
int proposedX = box.center.x - (box.size.width / 2);
int proposedY = box.center.y - (box.size.height / 2);
int proposedW = box.size.width;
int proposedH = box.size.height;

// Ensure top-left edge is within image
roi.x = proposedX < 0 ? 0 : proposedX;
roi.y = proposedY < 0 ? 0 : proposedY;

// Ensure bottom-right edge is within image
roi.width = 
   (roi.x - 1 + proposedW) > image.cols ? // Will this roi exceed image?
   (image.cols - 1 - roi.x)               // YES: make roi go to image edge
   : proposedW;                           // NO: continue as proposed
// Similar for height
roi.height = (roi.y - 1 + proposedH) > image.rows ? (image.rows - 1 - roi.y) : proposedH;

https://stackoverflow.com/questions/13803728/