#include <stdio.h>
#include<malloc.h> 

int main()

{
char firstCharacter;
char secondCharacter;
unsigned int FileSize,reserved,data_offset,size,width,height,padding,planes,bit_count,compression,image_size,i,j;

char padding= 8-(width*3)%8;

FILE * fp = fopen("D:\\flower.bmp","rb");

fread (&firstCharacter, sizeof(char), 1 ,fp);
fread (&secondCharacter, sizeof(char), 1 ,fp);
fread (&FileSize, sizeof(unsigned int), 1 ,fp);
fread (&reserved, sizeof(unsigned int), 1 ,fp);
fread (&data_offset, sizeof(unsigned int), 1 ,fp);
fread (&size, sizeof(unsigned int), 1 ,fp);
fread (&width, sizeof(unsigned int), 1 ,fp);
fread (&height, sizeof(unsigned int), 1 ,fp);
fread (&planes, sizeof(unsigned int), 1 ,fp);
fread (&bit_count, sizeof(unsigned int), 1 ,fp);
fread (&compression, sizeof(unsigned int), 1 ,fp);
fread (&image_size, sizeof(unsigned int), 1 ,fp);

printf("first character is %c \n", firstCharacter);
printf("second character is %c \n", secondCharacter);
printf("file size is %d \n", FileSize);
printf("reserved is %d \n", reserved);
printf("data offset is %d \n", data_offset);
printf("size is %d \n", size);
printf("file width is %d \n", width);
printf("file height is %d \n", height);

 fclose(fp); //always close the file whe you close

 char * image_data = malloc (size);
 fread (&width, size, 1, fp);

for(int i=0; i<(int) width, i++)
for(int j=0; j<(int) height, j++)
{
data_offset[i*(width*3+padding)+ (j*3)] = 0; // B color of first pixel
}

FILE * wp;
wp = fopen ("D:\\newfile.bmp", "wb");
fwrite (&firstCharacter, sizeof(char), 1, wp);
//write header information smae as u read
//write image pixel data which is already changed
fwrite(image_data, size,1, wp);
fclose(wp);
free(image_data);
}





BMP 파일을 오픈해서 RGB 중 Blue 를 0값 즉 검은색으로 변경후 새로운 BMP 파일 생성하는 프로그램