让图片在浏览器中只有被选中后才能看清

[图片上传失败] 

每隔一个像素进行反色而已

/*

File:      magicpic.c
Name:      让图片在浏览器中只有被选中后才能看清
Author:    zyl910
Blog:      http://blog.csdn.net/zyl910/
Version:   V1.0
Updata:    2006-12-27

*/

#include <stdio.h>
#include <conio.h>
#include <dos.h>

typedef unsigned char BYTE;
typedef unsigned int  WORD;
typedef unsigned long DWORD;
typedef BYTE _far  *LPBYTE;
typedef WORD _far  *LPWORD;
typedef DWORD _far *LPDWORD;

typedef long LONG;

typedef struct tagBITMAPFILEHEADER { // bmfh
 WORD    bfType;
 DWORD   bfSize;
 WORD    bfReserved1;
 WORD    bfReserved2;
 DWORD   bfOffBits;
} BITMAPFILEHEADER;

typedef struct tagBITMAPINFOHEADER{ // bmih
 DWORD  biSize;
 LONG   biWidth;
 LONG   biHeight;
 WORD   biPlanes;
 WORD   biBitCount;
 DWORD  biCompression;
 DWORD  biSizeImage;
 LONG   biXPelsPerMeter;
 LONG   biYPelsPerMeter;
 DWORD  biClrUsed;
 DWORD  biClrImportant;
} BITMAPINFOHEADER;
#define BI_RGB 0

typedef struct tagRGBQUAD { // rgbq
 BYTE    rgbBlue;
 BYTE    rgbGreen;
 BYTE    rgbRed;
 BYTE    rgbReserved;
} RGBQUAD;

int main(int argc, char* argv[])
{
 FILE *hf;
 BITMAPFILEHEADER bf;
 BITMAPINFOHEADER bi;
 long pLine, pCur;
 long ipixelbytes;
 long iscanbytes;
 int bline, b;
 BYTE byBuf[3];
 int i,j,k;

 printf("MagicPic V1.0 Copyright (c) 2006 by zyl910/n/n");

 if (argc < 2)
 {
  printf("Syntax: magicpic [filename]/n");
  return 0;
 }

 if ((hf=fopen(argv[1],"rb+"))==NULL)
 {
  printf("Can't Open File!/n");
  return 0;
 }

 do{
  if (!fread(&bf,sizeof(BITMAPFILEHEADER),1,hf))
  {
   printf("Error: BITMAPFILEHEADER/n");
   break;
  }

  if(0x4d42!=bf.bfType) // BM
  {
   printf("Error: Only BMP/n");
   break;
  }

  if (!fread(&bi,sizeof(BITMAPINFOHEADER),1,hf))
  {
   printf("Error: BITMAPINFOHEADER/n");
   break;
  }

  if(40!=bi.biSize)
  {
   printf("Error: Only BITMAPINFOHEADER/n");
   break;
  }

  if (bi.biWidth<=0 || bi.biHeight<=0)
  {
   printf("Error: Width/Height/n");
   break;
  }

  if (BI_RGB!=bi.biCompression || !(bi.biBitCount==24 || bi.biBitCount==32))
  {
   printf("Error: Only True Color(24bit/32bit)/n");
   break;
  }

  pLine = ftell(hf);
  ipixelbytes = bi.biBitCount / 8;
  iscanbytes = (ipixelbytes * bi.biWidth + 3) & -4;
  bline = (bi.biHeight ) & 1;
  for (i=0; i<bi.biHeight; i++)
  {
   pCur = pLine;
   b = bline;
   for(j=0; j<bi.biWidth; j++)
   {
    if (b)
    {
     fseek(hf, pCur, SEEK_SET);
     fread(&byBuf[0], 1, 3, hf);
     // 反色
     byBuf[2] = ~byBuf[2]; // R
     byBuf[1] = ~byBuf[1]; // G
     byBuf[0] = ~byBuf[0]; // B
     // 修改
     fseek(hf, pCur, SEEK_SET);
     fwrite(&byBuf[0], 1, 3, hf);
    }
    pCur += ipixelbytes;
    b = b^1;
   }
   pLine += iscanbytes;
   bline = bline^1;
  }
  printf("Succeed!/n");

 }while(0);
 fclose(hf);

 return 0;
}