README.md

Camera Calibration using OpenCV

This library facilitates calibration of cameras using OpenCV library.

Installation

Use the following commands to install the library. Make sure that OpenCV is installed

git clone https://github.com/unbeschwert/opencv-camera-calibration.git camera-calibration
cd camera-calibration
mkdir build && cd build
cmake ..
make
sudo make install

Important

1. The parameters for the calibrateCamera((std::function<cv::Mat(void *)> getImageFromSDK, void *handle) were used based on the Microsoft Azure Kinect SDK library. There, a device handle is used to capture images and video. Here is an example code for getImageFromSDK() :

cv::Mat getImageFromKamera(void* handle) {
    /*
     * This function is mainly designed to be used 
     * as a callback inside camera calibration library 
     * to get images from Kinect Kamera. Note that you can
     * rewrite this function to obtain images from any other camera. 
     * It is supposed to be a drop in replacement to provide a means to 
     * get images from any camera.
     */
    k4a::capture capture_handle;

    k4a::device *device_handle = reinterpret_cast<k4a::device*>(handle);
	
    if(not device_handle->get_capture(&capture_handle)) {
		std::cout << "Couldn't create handle for capture!\n";
		exit(1);
	}
    k4a::image rgb_image_handle = capture_handle.get_color_image();
    if(not rgb_image_handle.is_valid()) {
		std::cout << "Couldn't get an image!\n";
		exit(1);
	}
    
    uint32_t width = rgb_image_handle.get_width_pixels();
    uint32_t height = rgb_image_handle.get_height_pixels();

    uint8_t channels = rgb_image_handle.get_size() / 
        (width * height * sizeof(uint8_t));

    cv::Mat image(height, width, CV_MAKETYPE(
            cv::DataType<uint8_t>::type, channels));
    std::memcpy(mat.data, rgb_image_handle.get_buffer(),
            width * height * channels * sizeof(uint8_t));

    rgb_image_handle.reset();
    capture_handle.reset();
	
    return(image);
}

2. This library was only tested on linux. I would be glad if someone tests this on Windows and Mac OS.

Issues and Pull Requests

If you have any ideas about improvements or changes that might make this library better, please first create an issue so that we can discuss first.