OpenCV：找到二进制Mat图像的所有非零坐标

问题描述

我试图找到二进制图像的非零（x，y）坐标。

我发现几个对函数 countNonZero（）的引用，它只计算非零坐标和 findNonZero（）我不确定如何访问或使用，因为它似乎已完全从文档中删除。

是如何 findNonZero（）保存非零元素的说明。以下代码可用于访问二进制图片的非零坐标。方法1在OpenCV中使用 findNonZero（），方法2检查每个像素以找到非零值。

方法1：

  #include< iostream> 
 #include< opencv2 / core / core.hpp> 
 #include< opencv2 / highgui / highgui.hpp> 
 using namespace std; 
 using namespace cv; 
 
 int main（int argc，char ** argv）{
 Mat img = imread（binary image）; 
 Mat非零坐标; 
 findNonZero（img，nonZeroCoordinates）; 
 for（int i = 0; i  cout< 零＃<< i<< ：<<非零坐标。点>（i）.x< ，<非零坐标。点>（i）.y< endl; 
} 
 return 0; 
} 
  

方法2：
$ b

  #include< iostream> 
 #include< opencv2 / core / core.hpp> 
 #include< opencv2 / imgproc / imgproc.hpp> 
 #include< Opencv2 / highgui / highgui.hpp> 
 using namespace std; 
 using namespace cv; 
 
 int main（int argc，char ** argv）{
 Mat img = imread（binary image）; 
 for（int i = 0; i  for（int j = 0; j  if（img。 at< uchar>（j，i）== 255）{
 cout< i<< ，< j<< endl; //你的操作
} 
} 
} 
 return 0; 
} 
  

I'm atttempting to find the non-zero (x,y) coordinates of a binary image.

I've found a few references to the function countNonZero() which only counts the non-zero coordinates and findNonZero() which I'm unsure how to access or use since it seems to have been removed from the documentation completely.

This is the closest reference I found, but still not helpful at all. I would appreciate any specific help.

Edit:- To specify, this is using C++

解决方案

Here is an explanation for how findNonZero() saves non-zero elements. The following codes should be useful to access non-zero coordinates of your binary image. Method 1 used findNonZero() in OpenCV, and Method 2 checked every pixels to find the non-zero ones.

Method 1:

#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace std;
using namespace cv;

int main(int argc, char** argv) {
    Mat img = imread("binary image");
    Mat nonZeroCoordinates;
    findNonZero(img, nonZeroCoordinates);
    for (int i = 0; i < nonZeroCoordinates.total(); i++ ) {
        cout << "Zero#" << i << ": " << nonZeroCoordinates.at<Point>(i).x << ", " << nonZeroCoordinates.at<Point>(i).y << endl;
    }
    return 0;
}

Method 2:

#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace std;
using namespace cv;

int main(int argc, char** argv) {
    Mat img = imread("binary image");
    for (int i = 0; i < img.cols; i++ ) {
        for (int j = 0; j < img.rows; j++) {
            if (img.at<uchar>(j, i) == 255) {   
                cout << i << ", " << j << endl;     // Do your operations
            }
        }
    }
    return 0;
}

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