关于c语言实现图像的均值滤波 我处理后直接变马赛克了

#include <stdio.h>
#include <math.h>
#include <memory.h>
#include <conio.h>
#include <stdlib.h>
#include <windows.h>
#include "stdlib.h"
#include "string.h"
//原图象的宽度和高度
#define width 256
#define higth 256

int lvbo(unsigned char D[9])
{

	return (D[0]+D[1]+D[2]+D[3]+D[4]+D[5]+D[6]+D[7]+D[8])/9;
}

void main()
{
	FILE *fp,*newfp;
	int i,j;
	
	if(!(fp=fopen("D:\\Program Files\\Microsoft Visual Studio\\MyProjects\\jzlb\\Debug\\xrk.jpg","rb")))
	{
		printf("Open file1 error!\n");
		return ;
    }
	
	if(!(newfp=fopen("D:\\Program Files\\Microsoft Visual Studio\\MyProjects\\jzlb\\Debug\\2.jpg","wb")))
    {
        printf("Open file2 error!\n");
		return ;
    }
	
	unsigned char buffer[54+1024];//定义原图像头缓冲区
    fread(buffer,1,54+1024,fp);//读取文件头54个字节
	
	unsigned long length=width*higth;//图像的总象素个数
	unsigned char readData[higth][width];               //用于存储原图数据的数组
    unsigned char writeData[higth][width];               //用于存储原图数据的数组
	fread(&readData[0][0], sizeof(unsigned char),length, fp);//从原图读入数据
	
	for(i=0;i<higth;i++)
	{
		for(j=0;j<width;j++)
		{
            writeData[i][j]=readData[i][j];
		}
	}
	
	unsigned char D[9];        //定义选取框
	for(i=1;i<higth-1;i++)
	{
        for(j=1;j<width-1;j++)
        {
			D[0]=readData[i-1][j+1];
			D[1]=readData[i][j+1];
            D[2]=readData[i+1][j+1];
			D[3]=readData[i-1][j];
            D[4]=readData[i][j];
			D[5]=readData[i+1][j];
			D[6]=readData[i-1][j-1];
            D[7]=readData[i][j-1];
			D[8]=readData[i+1][j-1];
            writeData[i][j]=lvbo(D);
		}
    }
	
	fwrite(buffer,sizeof(unsigned char),54+1024,newfp);
	fwrite(writeData,sizeof(unsigned char),length,newfp);
	fclose(newfp);
	fclose(fp);
	printf("success\n");
	
	return ;
}