我有以下图片,并尝试使用这些行
找到OpenCV最大的矩形std::vector< std::vector<cv::Point> > contours;
cv::findContours(result,contours,CV_RETR_LIST,CV_CHAIN_APPROX_SIMPLE);
但上述语句会导致内存堆错误。任何人都可以告诉我为什么会发生这种情况?我最近几个小时都在伸展自己的头发。
我认为这与cv :: Point分配器有关,因为调用堆栈指示它。
更新:我刚刚使用CvFindContours运行程序而没有任何问题。所以它必须是OpenCV 2.3.1。
Update2:感谢@karlphillip的回答,我重新访问了我的项目,这是我的Visual Studio项目设置。由于恼人的memork泄漏消息,我将MFC链接为静态库。这就是问题的原因。当我使用MFC作为共享DLL时,问题就消失了。
答案 0 :(得分:2)
我刚刚在Linux和Windows XP(32位)上使用OpenCV 2.3.1测试了the following application,我没有遇到任何问题。
除非您可以编写一个最小的应用程序来重现您正在观察的问题,否则这就是我的目标。
这是input image,代码就在下面:
#include <cv.h>
#include <highgui.h>
using namespace cv;
double angle( cv::Point pt1, cv::Point pt2, cv::Point pt0 )
{
double dx1 = pt1.x - pt0.x;
double dy1 = pt1.y - pt0.y;
double dx2 = pt2.x - pt0.x;
double dy2 = pt2.y - pt0.y;
return (dx1*dx2 + dy1*dy2)/sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}
void find_squares(Mat& image, vector<vector<Point> >& squares)
{
// blur will enhance edge detection
Mat blurred(image);
medianBlur(image, blurred, 9);
Mat gray0(blurred.size(), CV_8U), gray;
vector<vector<Point> > contours;
// find squares in every color plane of the image
for (int c = 0; c < 3; c++)
{
int ch[] = {c, 0};
mixChannels(&blurred, 1, &gray0, 1, ch, 1);
// try several threshold levels
const int threshold_level = 2;
for (int l = 0; l < threshold_level; l++)
{
// Use Canny instead of zero threshold level!
// Canny helps to catch squares with gradient shading
if (l == 0)
{
Canny(gray0, gray, 10, 20, 3); //
// Dilate helps to remove potential holes between edge segments
dilate(gray, gray, Mat(), Point(-1,-1));
}
else
{
gray = gray0 >= (l+1) * 255 / threshold_level;
}
// Find contours and store them in a list
findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);
// Test contours
vector<Point> approx;
for (size_t i = 0; i < contours.size(); i++)
{
// approximate contour with accuracy proportional
// to the contour perimeter
approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);
// Note: absolute value of an area is used because
// area may be positive or negative - in accordance with the
// contour orientation
if (approx.size() == 4 &&
fabs(contourArea(Mat(approx))) > 1000 &&
isContourConvex(Mat(approx)))
{
double maxCosine = 0;
for (int j = 2; j < 5; j++)
{
double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
maxCosine = MAX(maxCosine, cosine);
}
if (maxCosine < 0.3)
squares.push_back(approx);
}
}
}
}
}
int main()
{
Mat img = imread("paper.jpg");
vector<vector<Point> > squares;
find_squares(img, squares);
std::cout << "squares size: " << squares.size() << std::endl;
getchar();
return 0;
}