Question

当我尝试创建一个cv :: Mat并在之后发布它（下面的代码）时，我仍然（根据valgrind）内存泄漏大约每个像素1个字节。

有谁知道如何正确释放cv :: Mat的内存？

感谢激光：）

代码：

int main(int argc, char** argv)
{
  cv::Mat* matrx = new cv::Mat(1000,1000,CV_8UC1,0.);
  matrx->release();
  delete matrx;
  return 0;
}

Valgrind的：

[...]
==29420==    1,000,028 bytes in 1 blocks are definitely lost in loss record 372 of 372
==29420==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==29420==    by 0x5438877: cv::fastMalloc(unsigned long) (in /usr/lib/x86_64-linux-gnu/libopencv_core.so.2.4.8)
==29420==    by 0x536FE2A: cv::Mat::create(int, int const*, int) (in /usr/lib/x86_64-linux-gnu/libopencv_core.so.2.4.8)
==29420==    by 0x426FB5: cv::Mat::create(int, int, int) (mat.inl.hpp:663)
==29420==    by 0x426ECD: cv::Mat::Mat(int, int, int, cv::Scalar_<double> const&) (mat.inl.hpp:347)
==29420==    by 0x425A09: main (main.cpp:18)
==29420== 
==29420== LEAK SUMMARY:
==29420==    definitely lost: 1,000,028 bytes in 1 blocks
==29420==    indirectly lost: 0 bytes in 0 blocks
==29420==      possibly lost: 5,072 bytes in 95 blocks
==29420==    still reachable: 304,758 bytes in 1,348 blocks
==29420==         suppressed: 0 bytes in 0 blocks
[...]

Answer 1

来自opencv github的反馈似乎很清楚：您使用OpenCV 3.x编译但在运行时使用OpenCV 2.4.8。由于它们不是二进制兼容的，因此它无法正确释放cv::Mat。让我们将LD_LIBRARY_PATH导出到用于编译的OpenCV 3.x的OCV_DIST/lib。

请注意，如果您delete指针，则之前甚至不需要release()。

Answer 2

从文档页面引用以下内容：（http://docs.opencv.org/2.4.9/modules/core/doc/basic_structures.html#mat-release）：

void Mat :: release（）该方法递减与矩阵数据相关联的参考计数器。当引用计数器达到0时，矩阵数据被释放，数据和引用计数器指针被设置为NULL。

上述意味着当你做＆＃34;删除matrx;＆＃34;您正在尝试删除已指向NULL的内存区域，这会生成运行时错误。

如何在C ++中完全释放cv :: Mat的内存

2 个答案: