// =================
// || Worksheet 2
// || In this example, we are going to modify some of the pixels of an image, and then save the new image to disk.
// =================

#include "program.h"

using namespace std;
using namespace cv;

int worksheettwo( Mat& colorImage )
{
    char my_window_name[] = "My Image";
    
    // now, we are going to convert our color image to a greyscale image, so that
    // we only have one channel.
    Mat greyImage;
    // OpenCV's convert color method.
    // usage: cvtColor(source, destination, conversion type);
    //cv::cvtColor( colorImage, greyImage, CV_BGR2GRAY );
    
    // First, we are going to create somewhere to store our modified image.
    
    cv::Mat outputImage;
 
    // initialize outputImage to be exactly the same size and content as greyImage.
    outputImage.create(colorImage.size(), colorImage.type());
    
    //now, we have loaded an image. let us manipulate some of the pixels.
    // what we are going to do is set every SECOND pixel
    
    // so, we are going to loop over all the rows
    for(int row = 0; row < colorImage.rows ; row++)
    {
        // and loop over each column
        for( int col = 0; col < colorImage.cols; col++)
        {
            // if j modulo 2 equals 0 (i.e. j is even)
            if( row % 2 == 0 )
            {
                // if it is even, then set the color to black (=0)
                
                // to set the value at of the image
                // usage: mat.at<type>(row, column, channel) = value;
                outputImage.at<float>(row,col) = 0;
            }
            // otherwise (if j is odd)
            else
            {
                // the use the color value of the original image.
                // copy the data from the input image and store it in the output image.
                outputImage.at<float>(row,col) = colorImage.at<float>(row,col);
            }
            
        } // end of the 'column' for loop

    } // end of the 'row' for loop
    
    cv::namedWindow( my_window_name, WINDOW_AUTOSIZE );
    
    // display our output image.
    cv::imshow( my_window_name, outputImage);
    
    // now we are going to save our image.
    // cv 'image write'
    // usage: imwrite( destination_file, image to save)
    //cv::imwrite( "images/Output_Image.jpg", outputImage );
    
    cv::waitKey();
    
    return 0;
}