find number of 1s in a binary cv::mat image

To find the number of 1s in a binary cv::Mat image in C++, you can follow these steps:

Initialize a counter variable: Start by initializing a variable to keep track of the number of 1s found in the image. Let's call this variable count and set its initial value to 0.
Iterate through the image: Use a nested loop to iterate through each pixel of the image. The outer loop will iterate over the rows, and the inner loop will iterate over the columns.
Access pixel values: Access the pixel value at each position using the at function of the cv::Mat object. The at function takes the row and column indices as parameters and returns the pixel value at that position.
Check if the pixel value is 1: Compare the pixel value obtained in the previous step with 1 using an if statement. If the pixel value is 1, increment the count variable by 1.
Repeat for all pixels: Continue the nested loop until you have checked all the pixels in the image.
Output the result: Once the loop has finished, the count variable will hold the total number of 1s in the image. You can then output this value to the console or use it for further processing.

Here is an example implementation of the above steps:

int countOnesInImage(const cv::Mat& image) {
    int count = 0;
    for (int row = 0; row < image.rows; row++) {
        for (int col = 0; col < image.cols; col++) {
            if (image.at<uchar>(row, col) == 1) {
                count++;
            }
        }
    }
    return count;
}

In this example, the countOnesInImage function takes a cv::Mat object as an argument and returns the number of 1s found in the image. The function iterates through each pixel of the image using nested loops, checks if the pixel value is 1, and increments the count variable accordingly. Finally, the function returns the count value as the result.