filter-more

// Detect edges
void edges(int height, int width, RGBTRIPLE image[height][width])
{
    // container for original image values
    RGBTRIPLE copy[height][width];

    // select row (height)
    for (int i = 0; i < height; i++)
    {
        // for each pixel in a row (width)
        for (int j = 0; j < width; j++)
        {
            // copy all image original values
            copy[i][j] = image[i][j];
        }
    }

    // select row (height)
    for (int i = 0; i < height; i++)
    {
        // for each pixel in a row (width)
        for (int j = 0; j < width; j++)
        {
            // intialize r g b Gx and Gy value holders and reset them at every j
            int GxR = 0, GxG = 0, GxB = 0, GyR = 0, GyG = 0, GyB = 0, counter = 0;

            //initialize Gx and Gy
            int Gx[] = {-1, 0, 1, -2, 0, 2, -1, 0, 1};
            int Gy[] = {-1, -2, -1, 0, 0, 0, 1, 2, 1};

            // loop all pixels adjacent (max 3 x 3)!
            for (int m = i - 1; m < i + 2; m++)
            {
                for (int n = j - 1; n < j + 2; n++)
                {
                    // set pixels past the border to 0
                    if (m < 0 || n < 0 || m > height || n > width)
                    {
                        copy[m][n].rgbtRed = 0; copy[m][n].rgbtGreen = 0, copy[m][n].rgbtBlue = 0;
                    }

                    GxR += copy[m][n].rgbtRed * Gx[counter], GxG += copy[m][n].rgbtGreen * Gx[counter], GxB += copy[m][n].rgbtBlue * Gx[counter];
                    GyR += copy[m][n].rgbtRed * Gy[counter], GyG += copy[m][n].rgbtGreen * Gy[counter], GyB += copy[m][n].rgbtBlue * Gy[counter];
                    counter++;
                }
            }
            image[i][j].rgbtRed = sqrt((GxR * GxR) + (GyR * GyR));
            if (image[i][j].rgbtRed > 255)
            {
                image[i][j].rgbtRed = 255; // cap the result to 8 bit (max 255)
            }
            image[i][j].rgbtGreen = sqrt((GxG * GxG) + (GyG * GyG));
            if (image[i][j].rgbtGreen > 255)
            {
                image[i][j].rgbtGreen = 255; // cap the result to 8 bit (max 255)
            }
            image[i][j].rgbtBlue = sqrt((GxB * GxB) + (GyB * GyB));
             if (image[i][j].rgbtBlue > 255)
            {
                image[i][j].rgbtBlue = 255; // cap the result to 8 bit (max 255)
            }
        }
    }
    return;
}