基于LSB的BMP文件信息隐藏

/********************************************* * 功能：基于LSB的BMP文件信息隐藏 * 作者：aikesiluoente * 构建日期： 2010/6/10 * 本程序参考自：“foxtail-处理bmp图象-2008/3/4” 在此表示感谢 *********************************************/ #include "Bmp24.h" #include <iostream> #include <string> #include <fstream> Bmp24::Bmp24(void) { _pbmfh = new tagBITMAPFILEHEADER; _pbmih = new tagBITMAPINFOHEADER; _pbmd = NULL; _size = 0; } Bmp24::~Bmp24(void) { delete _pbmfh; delete _pbmih; if (_pbmd) { delete _pbmd; } } //载入BMP文件 void Bmp24::LoadFile(const char *filename) { ifstream InFile; InFile.open(filename, ios::in | ios::binary); InFile.read((char*)_pbmfh, sizeof(tagBITMAPFILEHEADER)); cout << "+-----------+" << endl << "Read bmfh OK!" << endl; InFile.read((char*)_pbmih, sizeof(tagBITMAPINFOHEADER)); cout << "Read bmih OK!" << endl; //直接定位BMP数据区，跳过调色板 _size = _pbmfh->bfSize - _pbmfh->bfOffBits; _pbmd = new BYTE[_size]; InFile.read((char*)_pbmd, _size); cout << "Read bmd OK!" << endl; InFile.close(); cout << "Load file OK!" << endl << "+-----------+" << endl; } //保存BMP文件 void Bmp24::SaveFile(const char *filename) { ofstream OutFile; OutFile.open(filename, ios::out | ios::binary); OutFile.write((char*)_pbmfh, sizeof(tagBITMAPFILEHEADER)); cout << "+============+" << endl << "Write bmfh OK!" << endl; OutFile.write((char*)_pbmih, sizeof(tagBITMAPINFOHEADER)); cout << "Write bmih OK!" << endl; OutFile.write((char*)_pbmd, _size); cout << "Write bmd OK!" << endl; OutFile.close(); cout << "Save file OK!" << endl << "+============+" << endl; } //嵌入文本文件 void Bmp24::EmbedTxt(const char *filename) { ifstream TxtFile; TxtFile.open(filename, ios::in | ios::binary); TxtFile.seekg(0, TxtFile.end); DWORD TxtFileLength = TxtFile.tellg(); if (_size < TxtFileLength * 8) { return ; } cout << "M file length: " << TxtFileLength << endl; BYTE *pTxtFile = new BYTE[TxtFileLength]; TxtFile.seekg(0, TxtFile.beg); TxtFile.read((char*)pTxtFile, TxtFileLength); TxtFile.close(); for (int i = 0, k = 0; i < TxtFileLength; ++i) { for (int j = 0; j < 8; ++j) { if ((pTxtFile[i] >> j & 0x01) == 0) _pbmd[k+32] &= 0xfe; else _pbmd[k+32] |= 0x01; ++k; } } for (int i = 0; i < 32; ++i) { if ((TxtFileLength >> i & 0x00000001) == 0) _pbmd[i] &= 0xfe; else _pbmd[i] |= 0x01; } delete pTxtFile; cout << "Embedding file OK!" << endl; } //提取文本文件 void Bmp24::ExtractTxt(const char *filename) { DWORD TxtFileLength = 0x00000000; for (int i = 0; i < 32; ++i) { if ((_pbmd[i] & 0x01) == 0) TxtFileLength &= 0x7fffffff; else TxtFileLength |= 0x80000000; if (i < 31) TxtFileLength >>= 1; } cout << "M' file length: " << TxtFileLength << endl; BYTE *pTxtFile = new BYTE[TxtFileLength]; for (int i = 0, k = 0; i < TxtFileLength * 8; ++i) { if (i && i % 8 == 0) ++k; if ((_pbmd[i + 32] & 0x01) == 0) pTxtFile[k] &= 0x7f; else pTxtFile[k] |= 0x80; if (i % 8 != 7) pTxtFile[k] >>= 1; } ofstream TxtFile; TxtFile.open(filename, ios::out | ios::binary); TxtFile.write((char*)pTxtFile, TxtFileLength); TxtFile.close(); delete pTxtFile; cout << "Extrating file OK!" << endl; }