Save an image consisting of unsigned chars to a pgm file

write_pgm.c

void write_pgm(unsigned short id, unsigned char *buf, int width, int height) {
	char filename[1024];
	sprintf(filename, "%simage_%d.pgm", destinationPrefix, id);

	FILE *fp = fopen(filename, "wb");

	if (fp) {
		fprintf(fp, "P5\n%d %d\n%d\n", width, height, 0xFF);
		fwrite(buf, width * height, 1, fp);
		fclose(fp);
	}
}