helpers.c

#include "helpers.h"
#include <math.h>
void swap(int *a, int *b);

// Convert image to grayscale
void grayscale(int height, int width, RGBTRIPLE image[height][width])   //grayscale function
{
    for (int i = 0; i < height; i++)    //for loop to iterate over rows
    {
        for (int j = 0; j < width; j++)     //for loop to iterate over column(each pixel)
        {
            float Red = image[i][j].rgbtRed;    //take old value of red in each pixel and store it in new
            float Green = image[i][j].rgbtGreen;    //take old value of green in each pixel and store it in new
            float Blue = image[i][j].rgbtBlue;      //take old value of blue in each pixel and store it in new
            int avg = round((Red + Green + Blue) / 3);
            image[i][j].rgbtRed = avg;
            image[i][j].rgbtGreen = avg;
            image[i][j].rgbtBlue = avg;
        }
    }
    return;
}

// Convert image to sepia
void sepia(int height, int width, RGBTRIPLE image[height][width])
{
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            int originalRed = image[i][j].rgbtRed;
            int originalGreen = image[i][j].rgbtGreen;
            int originalBlue = image[i][j].rgbtBlue;
            int sepiaRed = round((.393 * originalRed) + (.769 * originalGreen) + (.189 * originalBlue));
            if (sepiaRed > 255)
            {
                image[i][j].rgbtRed = 255;
            }
            else
            {
                image[i][j].rgbtRed = sepiaRed;
            }
            int sepiaGreen = round((.349 * originalRed) + (.686 * originalGreen) + (.168 * originalBlue));
            if (sepiaGreen > 255)
            {
                image[i][j].rgbtGreen = 255;
            }
            else
            {
                image[i][j].rgbtGreen = sepiaGreen;
            }
            int sepiaBlue = round((.272 * originalRed) + (.534 * originalGreen) + (.131 * originalBlue));
            if (sepiaBlue > 255)
            {
                image[i][j].rgbtBlue = 255;
            }
            else
            {
                image[i][j].rgbtBlue = sepiaBlue;
            }
        }
    }
    return;
}

// Reflect image horizontally
void reflect(int height, int width, RGBTRIPLE image[height][width])
{
    int y = round(width / 2.0);
    RGBTRIPLE tmp[width];
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < y; j++)
        {
            tmp[j] = image[i][j];
            image[i][j] = image[i][width - 1 - j];
            image[i][width - 1 - j] = tmp[j];
        }
    }
    return;
}
void swap(int *a, int *b)
{
    int tempB = *a;
    *a = *b;
    *b = tempB;
}
void blur(int height, int width, RGBTRIPLE image[height][width])
{
    RGBTRIPLE temp[height][width];
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            temp[i][j] = image[i][j];
        }
    }
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            int sum_blue;
            int sum_green;
            int sum_red;
            float counter;
            sum_blue = sum_green = sum_red = counter = 0;
//CORNERS
            //corner pixel on bottom right
            if (i >= 0 && j >= 0)
            {
                sum_red += temp[i][j].rgbtRed;
                sum_green += temp[i][j].rgbtGreen;
                sum_blue += temp[i][j].rgbtBlue;
                counter++;
            }
            //corner pixel on bottom left
            if (i >= 0 && j - 1 >= 0)
            {
                sum_red += temp[i][j - 1].rgbtRed;
                sum_green += temp[i][j - 1].rgbtGreen;
                sum_blue += temp[i][j - 1].rgbtBlue;
                counter++;
            }
            //corner pixel on top left
            if (i - 1 >= 0 && j >= 0)
            {
                sum_red += temp[i - 1][j].rgbtRed;
                sum_green += temp[i - 1][j].rgbtGreen;
                sum_blue += temp[i - 1][j].rgbtBlue;
                counter++;
            }
            //corner pixel on top right
            if (i - 1 >= 0 && j - 1 >= 0)
            {
                sum_red += temp[i - 1][j - 1].rgbtRed;
                sum_green += temp[i - 1][j - 1].rgbtGreen;
                sum_blue += temp[i - 1][j - 1].rgbtBlue;
                counter++;
            }
//FOUR EDGES
            //pixels on bottom edge
            if ((i >= 0 && j + 1 >= 0) && (i >= 0 && j + 1 < width))
            {
                sum_red += temp[i][j + 1].rgbtRed;
                sum_green += temp[i][j + 1].rgbtGreen;
                sum_blue += temp[i][j + 1].rgbtBlue;
                counter++;
            }
            //pixels on top edge
            if ((i - 1 >= 0 && j + 1 >= 0) && (i - 1 >= 0 && j + 1 < width))
            {
                sum_red += temp[i - 1][j + 1].rgbtRed;
                sum_green += temp[i - 1][j + 1].rgbtGreen;
                sum_blue += temp[i - 1][j + 1].rgbtBlue;
                counter++;
            }
            //pixels on left edge
            if ((i + 1 >= 0 && j >= 0) && (i + 1 < height && j >= 0))
            {
                sum_red += temp[i + 1][j].rgbtRed;
                sum_green += temp[i + 1][j].rgbtGreen;
                sum_blue += temp[i + 1][j].rgbtBlue;
                counter++;
            }
            //pixels on right edge
            if ((i + 1 >= 0 && j - 1 >= 0) && (i + 1 < height && j - 1 >= 0))
            {
                sum_red += temp[i + 1][j - 1].rgbtRed;
                sum_green += temp[i + 1][j - 1].rgbtGreen;
                sum_blue += temp[i + 1][j - 1].rgbtBlue;
                counter++;
            }
//MIDDLE PIXELS
            //middle pixels
            if ((i + 1 >= 0 && j + 1 >= 0) && (i + 1 < height && j + 1 < width))
            {
                sum_red += temp[i + 1][j + 1].rgbtRed;
                sum_green += temp[i + 1][j + 1].rgbtGreen;
                sum_blue += temp[i + 1][j + 1].rgbtBlue;
                counter++;
            }
            //find average colour value
            image[i][j].rgbtRed = round(sum_red / counter);
            image[i][j].rgbtGreen = round(sum_green / counter);
            image[i][j].rgbtBlue = round(sum_blue / counter);
        }
    }
    return;
}