使用cv :: Mat类型时如何在图像上覆盖文本 [英] How to overlay text on image when working with cv::Mat type

问题描述

我正在使用opencv 2.1.在我的代码中，我存储了一些图像作为Mat对象存储，初始化如下:

I am using opencv 2.1. In my code I have a few images stored as Mat objects initialized like this:

Mat img1 = imread("img/stuff.pgm", CV_LOAD_IMAGE_GRAYSCALE);

完成矩阵运算后，可以使用imshow()正确显示它们.现在，我想在图像上添加一些文本来描述发生了什么.查看文档，看来cvPutText()将是我需要的功能.但是当我尝试这样的事情时:

I can display them properly using imshow() after my matrix operations are done. Now I want to add some text on the image to describe what has happened. Looking at the documentation it seems like cvPutText() would be the function I need. But when I try something like this:

cvPutText(result, "Differencing the two images.", cvPoint(30,30), &font, GREEN);

我收到以下编译错误: error: cannot convert ‘cv::Mat’ to ‘CvArr*’ for argument ‘1’ to ‘void cvPutText(CvArr*, const char*, CvPoint, const CvFont*, CvScalar)’

I get the following compile error: error: cannot convert ‘cv::Mat’ to ‘CvArr*’ for argument ‘1’ to ‘void cvPutText(CvArr*, const char*, CvPoint, const CvFont*, CvScalar)’

显示此图像时，我需要做些什么才能添加一些文本?

What do I need to do to be able to add some text when displaying this image?

推荐答案

我在看错地方.我在较新的 cpp的OpenCV文档中找到了答案.有一个名为putText()的新函数，该函数接受cv :: Mat对象.所以我尝试了这一行，它行得通:

I was looking at the wrong place. I found the answer in the newer OpenCV documentation for cpp. There is a new function called putText() that accepts cv::Mat objects. So I tried this line and it works:

putText(result, "Differencing the two images.", cvPoint(30,30), 
    FONT_HERSHEY_COMPLEX_SMALL, 0.8, cvScalar(200,200,250), 1, CV_AA);

希望这对某人有帮助.

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