一种二值图象无损压缩算法 南京理工大学电光学院 【摘 要】利用稀疏矩阵和差分编码对二色图像进行压缩保存

				/********************************************************************
				
					Created:	2006/12/09 12:32
					FileName: 	BMP.cpp
					Author:		Jar 包杰
					
					Purpose:	将24位BMP二色图像文件压缩
					
				*********************************************************************/
				#include "stdafx.h"
				#include "J.h"
				
				// 声明串行化过程
				IMPLEMENT_SERIAL(CJ, CObject, 0);
				
				CJ::CJ() 
				{
					JFileName = "";
					m_pBMFH = NULL;
					m_pBMIH = NULL;
					m_pBits = NULL;
					m_pJFH = NULL;
				}
				
				CJ::~CJ()
				{
					if (m_pBMFH != NULL)
					{
						delete m_pBMFH;
						m_pBMFH = NULL;
					}
					if (m_pBMIH != NULL)
					{
						delete m_pBMIH;
						m_pBMIH = NULL;
					}
					if(m_pBits != NULL)
					{
						m_pBits = NULL;
					}
					if(m_pJFH != NULL)
					{
						m_pJFH = NULL;
					}
				}
				
				/*************************************************
				Function:		Read
				Description:	读取BMP图像
				Input:			CFile *pFile
				Output:         
				Return:			BOOL 成功返回TRUE，否则返回FALSE
				Others:			读取BMP文件头、信息头和图像数据 
				*************************************************/
				BOOL CJ::BMPRead(CFile *pFile)
				{
					int nSize = sizeof(BITMAPFILEHEADER);
					m_pBMFH = (LPBITMAPFILEHEADER) new BYTE[nSize];
				
					//创建J文件头
					nSize = sizeof(JFILEHEADER);
					m_pJFH = (LPJFILEHEADER) new BYTE[nSize];
				
					//读取文件头
					pFile->Read(m_pBMFH, sizeof(BITMAPFILEHEADER));
					// 判断是否是BMP格式的位图
					if(m_pBMFH->bfType != BMP_HEADER_MARKER)
						return FALSE;
				
					nSize = sizeof(BITMAPINFOHEADER);
					m_pBMIH = (LPBITMAPINFOHEADER) new BYTE[nSize];
				
					//生成.J文件名
					JFileName=pFile->GetFileName()+".j01";
				
					//读取信息头
					pFile->Read(m_pBMIH, sizeof(BITMAPINFOHEADER));
					//非24位图像打开失败
					if (m_pBMIH->biBitCount != 24)
						return FALSE;
				
					//读取图象数据
					m_pBits = (LPBYTE) new BYTE[m_pBMIH->biSizeImage];
					pFile->Read(m_pBits, m_pBMIH->biSizeImage);
				
					return TRUE;
				}
				
				/*************************************************
				Function:		JWrite
				Description:	压缩BMP图像
				Input:			*pDC
				Output:         
				Return:			BOOL 成功返回TRUE，否则返回FALSE
				Others:			第一次扫描将BMP图像转换成二值矩阵，只含'0''1'
								
				*************************************************/
				bool CJ::JWrite(CDC *pDC)
				{
					int i,j;
					BYTE *DivH,*DivMatrix;
					DivMatrix = new BYTE[m_pBMIH->biHeight*m_pBMIH->biWidth];	//二值矩阵
					LPBYTE BitsH = m_pBits;
					DivH = DivMatrix;	//标记数据区开始，防止刷新时越界
				
					m_pJFH->JType = J_HEADER_MARKER;
					m_pJFH->JHeight = (WORD)m_pBMIH->biHeight;
					m_pJFH->JWidth = (WORD)m_pBMIH->biWidth;
					for (i = 0;i						m_pJFH->FirstColor[i] = *(m_pBits+i);
				
					//转换成二值矩阵
					for (i = 0;ibiHeight;i++)
					{
						for (j = 0;jbiWidth;j++)
						{
							BYTE tmp = *m_pBits++;
							m_pBits++;m_pBits++;
							if (tmp != m_pJFH->FirstColor[0])
							{
								*DivMatrix++ = 1;
								pDC->SetPixel(j,m_pBMIH->biHeight-i,RGB(0,0,0));
							}
							else
							{
								*DivMatrix++ = 0;
								pDC->SetPixel(j,m_pBMIH->biHeight-i,RGB(255,255,255));
							}
						}
						m_pBits = m_pBits+m_pBMIH->biWidth%4;
					}
					m_pBits = BitsH;
					DivMatrix = DivH;
				
					CFile JFile;
					JFile.Open(JFileName,CFile::modeCreate|CFile::modeReadWrite);
					JFile.Write(m_pJFH,sizeof(JFILEHEADER));
					for (i = 0;ibiHeight;i++)
					{
						for (j = 0;jbiWidth;j++)
						{
							JFile.Write(DivMatrix++,1);
						}
					}
					JFile.Close();
					return TRUE;
				}
				
				//串行化
				void CJ::Serialize(CArchive &ar)
				{
					BMPRead(ar.GetFile());
				}
				
				//获取文件头指针　
				LPJFILEHEADER CJ::GetJFH()
				{
					return m_pJFH;
				}