如何在C中做一个ppm文件的黑白图片？

#include <stdio.h>
#include <stdlib.h>

#define WIDTH  512
#define HEIGHT 512

unsigned char image[HEIGHT][WIDTH];

for (int i = 0; i < HEIGHT; i++) {
    for (int j = 0; j < WIDTH; j++) {
        image[i][j] = 0;
    }
}

image[100][200] = 255;  // 示例：将第100行第200列的像素点设置为白色

FILE *file = fopen("image.ppm", "wb");
if (file == NULL) {
    printf("无法创建文件！\n");
    exit(1);
}

fprintf(file, "P6\n");
fprintf(file, "%d %d\n", WIDTH, HEIGHT);
fprintf(file, "255\n");

for (int i = 0; i < HEIGHT; i++) {
    for (int j = 0; j < WIDTH; j++) {
        fputc(image[i][j], file);
        fputc(image[i][j], file);
        fputc(image[i][j], file);
    }
}

fclose(file);