使用 openCV Mat c++ 加载图像

问题描述

我想在 openCV 中使用 Mat 加载图像

I want to load an image using Mat in openCV

我的代码是:

Mat I = imread("C:/images/apple.jpg", 0);
namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
imshow( "Display window", I ); 

我在消息框中收到以下错误:

I am getting the following error in a message box:

Unhandled exception at 0x70270149 in matching.exe: 0xC0000005: Access violation 
reading location 0xcccccccc.

请注意，我包括:

#include <cv.h>
#include <cxcore.h>
#include <highgui.h>
#include <iostream>
#include <math.h>

推荐答案

我已经讨论过这个之前很多次，我想再次这样做是没有意义的，但是防御性代码:如果一个方法/函数调用可能会失败，请确保您知道它何时发生:

I've talked about this so many times before, I guess it's pointless to do it again, but code defensively: if a method/function call can fail, make sure you know when it happens:

Mat I = imread("C:\images\apple.jpg", 0);
if (I.empty())
{
    std::cout << "!!! Failed imread(): image not found" << std::endl;
    // don't let the execution continue, else imshow() will crash.
}

namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
imshow( "Display window", I ); 
waitKey(0);

请注意，Windows 的路径使用反斜杠 而不是 *nix 系统上使用的标准 /.传递文件名时需要转义反斜杠:C:\images\apple.jpg

Note that Windows' path uses backslash instead of the standard / used on *nix systems. You need to escape the backslash when passing the filename: C:\images\apple.jpg

如果您使用 imshow()，则必须调用 waitKey().

Calling waitKey() is mandatory if you use imshow().

编辑:

如果 cv::imread() 抛出异常我知道唯一可行的解决方案是下载 OpenCV 源代码并在机器上构建它，因为重新- 安装 OpenCV 不能解决问题.

If it's cv::imread() that is throwing the exception the only solution I know to work is downloading OpenCV sources and building it on the machine, since re-installing OpenCV doesn't fix the issue.

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