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Created January 19, 2021 18:15
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Pset 4 Filter | CS50 2021
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helper.c
// Aryan Chaurasia
// CS50 2021 Pset 4 filter less
// 13 Jan 2021
#include "helpers.h"
#include <math.h>
// Convert image to grayscale
void grayscale(int height, int width, RGBTRIPLE image[height][width])
{
// calculates average
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
int averageValue = round(((image[i][j].rgbtRed + image[i][j].rgbtGreen + image[i][j].rgbtBlue) / 3.0));
image[i][j].rgbtRed = averageValue;
image[i][j].rgbtGreen = averageValue;
image[i][j].rgbtBlue = averageValue;
}
}
return;
}
// Convert image to sepia
void sepia(int height, int width, RGBTRIPLE image[height][width])
{
for (int i = 0; i < height; i++)
{
// calculates sepia according to the formular
for (int j = 0; j < width; j++)
{
int sepiaRed = round((0.393 * image[i][j].rgbtRed) + (0.769 * image[i][j].rgbtGreen) + (0.189 * image[i][j].rgbtBlue));
int sepiaGreen = round((0.349 * image[i][j].rgbtRed) + (0.686 * image[i][j].rgbtGreen) + (0.168 * image[i][j].rgbtBlue));
int sepiaBlue = round((0.272 * image[i][j].rgbtRed) + (0.534 * image[i][j].rgbtGreen) + (0.131 * image[i][j].rgbtBlue));
// if value is greater than 255
// then the value is set to 255 which is the max
if (sepiaRed >= 255)
{
sepiaRed = 255;
}
if (sepiaGreen >= 255)
{
sepiaGreen = 255;
}
if (sepiaBlue >= 255)
{
sepiaBlue = 255;
}
image[i][j].rgbtRed = sepiaRed;
image[i][j].rgbtGreen = sepiaGreen;
image[i][j].rgbtBlue = sepiaBlue;
}
}
return;
}
// Reflect image horizontally
void reflect(int height, int width, RGBTRIPLE image[height][width])
{
typedef struct
{
BYTE rgbtBlue;
BYTE rgbtGreen;
BYTE rgbtRed;
}
temp;
temp tempimage[height][width];
// uses tempimages to shift and reflect pixel
for (int i = 0; i < height; i++)
{
for (int j = 0; j < (width / 2); j++)
{
tempimage[i][j].rgbtRed = image[i][j].rgbtRed;
image[i][j].rgbtRed = image[i][width - j - 1].rgbtRed;
image[i][width - j - 1].rgbtRed = tempimage[i][j].rgbtRed;
tempimage[i][j].rgbtBlue = image[i][j].rgbtBlue;
image[i][j].rgbtBlue = image[i][width - j - 1].rgbtBlue;
image[i][width - j - 1].rgbtBlue = tempimage[i][j].rgbtBlue;
tempimage[i][j].rgbtGreen = image[i][j].rgbtGreen;
image[i][j].rgbtGreen = image[i][width - j - 1].rgbtGreen;
image[i][width - j - 1].rgbtGreen = tempimage[i][j].rgbtGreen;
}
}
return;
}
// Blur image
void blur(int height, int width, RGBTRIPLE image[height][width])
{
typedef struct
{
BYTE rgbtBlue;
BYTE rgbtGreen;
BYTE rgbtRed;
}
temp;
temp tempimage[height][width];
// copies image in tempimage so can calculate blur effect without modifying original RGB values
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
tempimage[i][j].rgbtRed = image[i][j].rgbtRed;
tempimage[i][j].rgbtBlue = image[i][j].rgbtBlue;
tempimage[i][j].rgbtGreen = image[i][j].rgbtGreen;
}
}
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
// if the colour is in first line and left corner
if (i == 0 && j == 0)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j + 1].rgbtRed + tempimage[i + 1][j].rgbtRed +
tempimage[i + 1][j + 1].rgbtRed) / 4.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j + 1].rgbtGreen + tempimage[i + 1][j].rgbtGreen +
tempimage[i + 1][j + 1].rgbtGreen) / 4.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j + 1].rgbtBlue + tempimage[i + 1][j].rgbtBlue +
tempimage[i + 1][j + 1].rgbtBlue) / 4.0));
}
// if the pixel is in first line but on right corner
else if (i == 0 && j == width - 1)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j - 1].rgbtRed + tempimage[i + 1][j].rgbtRed +
tempimage[i + 1][j - 1].rgbtRed) / 4.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j - 1].rgbtGreen + tempimage[i + 1][j].rgbtGreen +
tempimage[i + 1][j - 1].rgbtGreen) / 4.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j - 1].rgbtBlue + tempimage[i + 1][j].rgbtBlue +
tempimage[i + 1][j - 1].rgbtBlue) / 4.0));
}
// if the pixel is in last line and left corner
else if (j == 0 && i == height - 1)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j + 1].rgbtRed + tempimage[i - 1][j].rgbtRed +
tempimage[i - 1][j + 1].rgbtRed) / 4.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j + 1].rgbtGreen + tempimage[i - 1][j].rgbtGreen +
tempimage[i - 1][j + 1].rgbtGreen) / 4.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j + 1].rgbtBlue + tempimage[i - 1][j].rgbtBlue +
tempimage[i - 1][j + 1].rgbtBlue) / 4.0));
}
// if the pixel is in last line and Right corner
else if (i == height - 1 && j == width - 1)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j - 1].rgbtRed + tempimage[i - 1][j].rgbtRed +
tempimage[i - 1][j - 1].rgbtRed) / 4.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j - 1].rgbtGreen + tempimage[i - 1][j].rgbtGreen +
tempimage[i - 1][j - 1].rgbtGreen) / 4.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j - 1].rgbtBlue + tempimage[i - 1][j].rgbtBlue +
tempimage[i - 1][j - 1].rgbtBlue) / 4.0));
}
// if the pixel is in first line (this is for calculating blur in edge)
else if (i == 0)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j - 1].rgbtRed + tempimage[i][j + 1].rgbtRed + tempimage[i +
1][j].rgbtRed +
tempimage[i + 1][j - 1].rgbtRed + tempimage[i + 1][j + 1].rgbtRed) / 6.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j - 1].rgbtGreen + tempimage[i][j + 1].rgbtGreen +
tempimage[i + 1][j].rgbtGreen +
tempimage[i + 1][j - 1].rgbtGreen + tempimage[i + 1][j + 1].rgbtGreen) / 6.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j - 1].rgbtBlue + tempimage[i][j + 1].rgbtBlue + tempimage[i
+
1][j].rgbtBlue +
tempimage[i + 1][j - 1].rgbtBlue + tempimage[i + 1][j + 1].rgbtBlue) / 6.0));
}
// if the pixel is in last line (this is for calculating blur in edge)
else if (i == height - 1)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j - 1].rgbtRed + tempimage[i][j + 1].rgbtRed + tempimage[i -
1][j].rgbtRed +
tempimage[i - 1][j - 1].rgbtRed + tempimage[i - 1][j + 1].rgbtRed) / 6.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j - 1].rgbtGreen + tempimage[i][j + 1].rgbtGreen +
tempimage[i -
1][j].rgbtGreen +
tempimage[i - 1][j - 1].rgbtGreen + tempimage[i - 1][j + 1].rgbtGreen) / 6.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j - 1].rgbtBlue + tempimage[i][j + 1].rgbtBlue + tempimage[i
-
1][j].rgbtBlue +
tempimage[i - 1][j - 1].rgbtBlue + tempimage[i - 1][j + 1].rgbtBlue) / 6.0));
}
// If the pixel is in the left side and on edge
else if (j == 0)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i - 1][j].rgbtRed + tempimage[i + 1][j].rgbtRed + tempimage[i][j +
1].rgbtRed +
tempimage[i - 1][j + 1].rgbtRed + tempimage[i + 1][j + 1].rgbtRed) / 6.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i - 1][j].rgbtGreen + tempimage[i + 1][j].rgbtGreen +
tempimage[i][j + 1].rgbtGreen +
tempimage[i - 1][j + 1].rgbtGreen + tempimage[i + 1][j + 1].rgbtGreen) / 6.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i - 1][j].rgbtBlue + tempimage[i + 1][j].rgbtBlue +
tempimage[i][j + 1].rgbtBlue +
tempimage[i - 1][j + 1].rgbtBlue + tempimage[i + 1][j + 1].rgbtBlue) / 6.0));
}
// if the pixel is on the right side and on the edge
else if (j == width - 1)
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i - 1][j].rgbtRed + tempimage[i + 1][j].rgbtRed + tempimage[i][j -
1].rgbtRed +
tempimage[i - 1][j - 1].rgbtRed + tempimage[i + 1][j - 1].rgbtRed) / 6.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i - 1][j].rgbtGreen + tempimage[i + 1][j].rgbtGreen +
tempimage[i][j - 1].rgbtGreen +
tempimage[i - 1][j - 1].rgbtGreen + tempimage[i + 1][j - 1].rgbtGreen) / 6.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i - 1][j].rgbtBlue + tempimage[i + 1][j].rgbtBlue +
tempimage[i][j - 1].rgbtBlue +
tempimage[i - 1][j - 1].rgbtBlue + tempimage[i + 1][j - 1].rgbtBlue) / 6.0));
}
// otherwise take all 9 side average to calculate blur
else
{
image[i][j].rgbtRed = round(((tempimage[i][j].rgbtRed + tempimage[i][j - 1].rgbtRed + tempimage[i][j + 1].rgbtRed + tempimage[i -
1][j].rgbtRed +
tempimage[i - 1][j - 1].rgbtRed + tempimage[i - 1][j + 1].rgbtRed + tempimage[i + 1][j].rgbtRed
+ tempimage[i + 1][j + 1].rgbtRed + tempimage[i + 1][j - 1].rgbtRed) / 9.0));
image[i][j].rgbtGreen = round(((tempimage[i][j].rgbtGreen + tempimage[i][j - 1].rgbtGreen + tempimage[i][j + 1].rgbtGreen +
tempimage[i - 1][j].rgbtGreen +
tempimage[i - 1][j - 1].rgbtGreen + tempimage[i - 1][j + 1].rgbtGreen + tempimage[i + 1][j].rgbtGreen
+ tempimage[i + 1][j + 1].rgbtGreen + tempimage[i + 1][j - 1].rgbtGreen) / 9.0));
image[i][j].rgbtBlue = round(((tempimage[i][j].rgbtBlue + tempimage[i][j - 1].rgbtBlue + tempimage[i][j + 1].rgbtBlue +
tempimage[i - 1][j].rgbtBlue +
tempimage[i - 1][j - 1].rgbtBlue + tempimage[i - 1][j + 1].rgbtBlue + tempimage[i + 1][j].rgbtBlue
+ tempimage[i + 1][j + 1].rgbtBlue + tempimage[i + 1][j - 1].rgbtBlue) / 9.0));
}
}
}
return;
}
// Comments
// comments
// comments
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