bmp.cpp

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:	读BMP+显示功能+压缩成J文件
	
*********************************************************************/
#include "stdafx.h"
#include "BMP.h"

// 声明串行化过程
IMPLEMENT_SERIAL(CBmp, CObject, 0);

CBmp::CBmp() 
{
	m_pBMFH = NULL;
	m_pBMIH = NULL;
	m_pBits = NULL;
}

CBmp::~CBmp()
{
	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;
	}
}

/*************************************************
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 CBmp::BMPRead(CFile *pFile)
{
	int nSize = sizeof(BITMAPFILEHEADER);
	m_pBMFH = (LPBITMAPFILEHEADER) 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()+".j";

	//读取信息头
	pFile->Read(m_pBMIH, sizeof(BITMAPINFOHEADER));

	//读取图象数据
	m_pBits = (LPBYTE) new BYTE[m_pBMIH->biSizeImage];
	pFile->Read(m_pBits, m_pBMIH->biSizeImage);

	return TRUE;
}

//显示图像和压缩图像
void CBmp::BMPDraw_JWrite(CDC *pDC)
{
	int i,j;
	LPBYTE tmpBit = m_pBits;	//标记数据区开始，防止刷新时越界

	CString s;
	s.Format("Size = %d Byte",m_pBMFH->bfSize);
	pDC->TextOut(0,0,s);
	s.Format("Width = %d pix",m_pBMIH->biWidth);
	pDC->TextOut(0,20,s);
	s.Format("Height = %d pix",m_pBMIH->biHeight);
	pDC->TextOut(0,40,s);
	s.Format("成功压缩!");
	pDC->TextOut(0,60,s);
	
	for (i = 0;i<m_pBMIH->biHeight;i++)
	{
		for (j = 0;j<m_pBMIH->biWidth;j++)
		{
			BYTE b = *m_pBits++;
			BYTE g = *m_pBits++;
			BYTE r = *m_pBits++;
			pDC->SetPixel(j,m_pBMIH->biHeight-i+80,RGB(r,g,b));
		}
		m_pBits = m_pBits+m_pBMIH->biWidth%4;
	}
	m_pBits = tmpBit;

	//创建压缩的.J文件
	CFile JFile;
	if(!JFile.Open(JFileName,CFile::modeReadWrite))
	{
		JFile.Open(JFileName,CFile::modeCreate|CFile::modeReadWrite);	
	}

	//写入J文件头
	int nSize = sizeof(JFILEHEADER);
	m_pJFH = (LPJFILEHEADER) new BYTE[nSize];
	m_pJFH->JType = J_HEADER_MARKER;
	m_pJFH->JHeight = (WORD)m_pBMIH->biHeight;
	m_pJFH->JWidth = (WORD)m_pBMIH->biWidth;
	JFile.Write(m_pJFH, sizeof(JFILEHEADER));

	//第一次扫描文件
	for (i = 0;i<m_pBMIH->biHeight;i++)
	{
		for (j = 0;j<m_pBMIH->biWidth;j++)
		{
			BYTE b = *m_pBits++;
			BYTE g = *m_pBits++;
			BYTE r = *m_pBits++;
			if (r==0) 
			{
				JFile.Write(&i, sizeof(int));
				JFile.Write(&j, sizeof(int));
			}
		}
		m_pBits = m_pBits+m_pBMIH->biWidth%4;
	}
	m_pBits = tmpBit;

	JFile.Close();

}
//串行化
void CBmp::Serialize(CArchive &ar)
{
	BMPRead(ar.GetFile());
}

//获取信息头指针　
LPBITMAPINFOHEADER CBmp::GetBMIH()
{
	return m_pBMIH;
}