Using the 3 files below, edit the C++ functions that will manipulate a 600x600 image.

The original image should be resized twice, down to both 400x400 and 200x200 atop the newly created 600x600 P6 image. The function prototype for the resizings should be: void resizeImage(image_t*, image_t* );

***************************************

// driver.c //

#include

#include

#include "ppm_info.h"

int main(int argc, char* argv[])

{

if(argc != 4)

{

printf("USAGE: ");

return -1;

}

FILE* originalImage = fopen(argv[1], "r");

FILE* newImage = fopen(argv[2], "w");

FILE* newImageP3 = fopen(argv[3], "w");

if(!originalImage || !newImage || !newImageP3)

{

printf("ERROR: File(s) could not be opened. ");

return -1;

}

image_t* image = read_ppm(originalImage);

header_t hdr = {"P6", 600, 600, 255};

image_t* imageNew = allocate_memory(hdr);

resizeImage(image, imageNew);

write_p6(newImage, imageNew);

//write_p6(newImage, image);

//write_p3(newImageP3, image);

return 0;

}

******************************************************************

// ppm_info.c //

#include "ppm_info.h"

header_t read_header(FILE* image_file)

{

header_t header;

fscanf(image_file, "%s %d %d %d ",

header.magicNum, &header.width, &header.height, &header.maxVal);

return header;

}

void write_header(FILE* out_file, header_t header)

{

fprintf(out_file, "%s %d %d %d ",

header.magicNum, header.width, header.height, header.maxVal);

}

image_t* read_ppm(FILE* image_file)

{

header_t header = read_header(image_file);

image_t* image = NULL;

image = read_pixels(image_file, header);

return image;

}

image_t* read_pixels(FILE* image_file, header_t header) {

int row = 0;

int col = 0;

unsigned char red,green,blue;

red = green = blue = 0;

image_t* image= allocate_memory(header);

for(row = 0; row < header.height; row++)

{

for(col = 0; col < header.width; col++)

{

fscanf(image_file, "%c%c%c", &red, &green, &blue);

image->pixels[row][col].r = red;

image->pixels[row][col].g = green;

image->pixels[row][col].b = blue;

}

}

return image;

}

image_t* allocate_memory(header_t header)

{

int row;

/*First allocate memory for the image itself. The image has a header and

*a double pointer for the pixels */

image_t* image = (image_t*) malloc(sizeof(image_t));

/*After you have allocated the memory for the image you can now set the header

*equal to the header passed in.*/

image->header = header;

/*Now we need to allocate the memory for the actual pixels. This is a 2d

*array so allocate for the 2D array. */

image->pixels = (pixel_t**) malloc(sizeof(pixel_t*) * header.height);

for(row = 0; row < header.height; row++)

{

image->pixels[row] = (pixel_t*)malloc(sizeof(pixel_t) * header.width);

}

return image;

}

void write_p6(FILE* out_file, image_t* image)

{

int row = 0;

int col = 0;

//unsigned char red,green,blue;

header_t header = image->header;

strcpy(header.magicNum,"P6");

write_header(out_file, header);

//red = green = blue = 0;

/*Loop through the image and print each pixel*/

for(row = 0; row < header.height; row++)

{

for(col = 0; col < header.width; col++)

{

fprintf(out_file, "%c%c%c",

image->pixels[row][col].r,

image->pixels[row][col].g,

image->pixels[row][col].b);

}

}

}

void write_p3(FILE* out_file, image_t* image)

{

int row = 0;

int col = 0;

//unsigned char red,green,blue;

header_t header = image->header;

strcpy(header.magicNum,"P3");

write_header(out_file, header);

//red = green = blue = 0;

/*Loop through the image and print each pixel*/

for(row = 0; row < header.height; row++)

{

for(col = 0; col < header.width; col++)

{

fprintf(out_file, "%d %d %d ",

image->pixels[row][col].r,

image->pixels[row][col].g,

image->pixels[row][col].b);

}

}

}

void resizeImage(image_t* old, image_t* resized)

{

double relW = (double)(old->header.width/resized->header.width);

double relH; //do the same as above with height

int row, col;

for(row = 0; row < resized->header.height; row++)

{

for(col = 0; col < resized->header.width; col++)

{

//calculate newrow and newcol

//set resized->pixels[row][col] = old->pixels[newrow][newcol];

}

}

}

************************************************************************

// ppm_info.h //

#ifndef PPM_INFO

#define PPM_INFO

#include

#include

#include

// First meaningful line of the PPM file

typedef struct header {

char magicNum[3];

int width, height, maxVal;

} header_t;

// Represents an RGB pixel with integer values between 0-255

typedef struct pixel {

unsigned char r, g, b;

} pixel_t;

// PPM Image representation

typedef struct image {

header_t header;

pixel_t** pixels;

} image_t;

header_t read_header(FILE* image_file);

void write_header(FILE* out_file, header_t header);

image_t* read_ppm(FILE* image_file);

image_t* read_pixels(FILE* image_file, header_t header);

image_t* allocate_memory(header_t header);

void write_p6(FILE* out_file, image_t* image);

void write_p3(FILE* out_file, image_t* image);

/*Add resizeImage prototype from specification document*/

#endif