InterfaceWithOpenCV.cpp

Example for interfaceing with OpenCV Mat

#include "NumCpp.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
 
#include <iostream>
#include <numeric>
 
 
constexpr nc::uint32 NUM_ROWS = 512;
constexpr nc::uint32 NUM_COLS = 512;
 
int main()
{
    // create a ramp image with NumCpp
    constexpr auto numHalfCols = NUM_COLS / 2; // integer division
    auto           ncArray     = nc::NdArray<nc::uint8>(NUM_ROWS, NUM_COLS);
    for (nc::uint32 row = 0; row < ncArray.numRows(); ++row)
    {
        auto begin = ncArray.begin(row);
        std::iota(begin, begin + numHalfCols, nc::uint8{ 0 });
 
        auto rbegin = ncArray.rbegin(row);
        std::iota(rbegin, rbegin + numHalfCols, nc::uint8{ 0 });
    }
 
    // convert to OpenCV Mat
    auto cvArray = cv::Mat(ncArray.numRows(), ncArray.numCols(), CV_8SC1, ncArray.data());
 
    // display the OpenCV Mat
    cv::namedWindow("Display window", cv::WINDOW_AUTOSIZE); // Create a window for display.
    cv::imshow("Display window", cvArray);                  // Show our image inside it.
    cv::waitKey(0);                                         // Wait for a keystroke in the window
 
    // tranpose the Mat with OpenCV
    auto transposedCvArray = cv::Mat(cvArray.cols, cvArray.rows, CV_8SC1);
    cv::transpose(cvArray, transposedCvArray);
 
    // display the transposed Mat
    cv::namedWindow("Display window", cv::WINDOW_AUTOSIZE); // Create a window for display.
    cv::imshow("Display window", transposedCvArray);        // Show our image inside it.
    cv::waitKey(0);                                         // Wait for a keystroke in the window
 
    // convert the transposed OpenCV Mat to a NumCpp array
    auto transposedNcArray =
        nc::NdArray<nc::uint8>(transposedCvArray.data, transposedCvArray.rows, transposedCvArray.cols);
 
    // make sure the two transposed arrays are the same
    if (nc::array_equal(transposedNcArray, ncArray.transpose()))
    {
        std::cout << "Arrays are equal.\n";
    }
    else
    {
        std::cout << "Arrays are not equal.\n";
    }
 
    return 0;
}