C++ 读取bmp图片示例程序

// scBmp.cpp: implementation of the scBmp class. // ////////////////////////////////////////////////////////////////////// #include "stdafx.h" #include "scBmp.h" #ifdef _DEBUG #undef THIS_FILE static char THIS_FILE[]=__FILE__; #define new DEBUG_NEW #endif ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// scBmp::scBmp() { this->m_bmpSize.bmpHeight=0; this->m_bmpSize.bmpWidth=0; this->m_bmpSize.BitCount=0; this->m_bmpSize.BytesPerLine=0; } scBmp::~scBmp() { } bool scBmp::Read(const char *FileName) { fstream file; file.open(FileName,ios::binary | ios::in | ios::nocreate); if(file.fail()) { file.close(); return false; } // 尝试读取DIB文件头 file.read((char*)&m_bmfHeader,sizeof(BITMAPFILEHEADER)); // 判断是否是DIB对象，检查头两个字节是否是"BM" if(m_bmfHeader.bfType!=0x4d42) { file.close(); return false; } BITMAPINFOHEADER bi; file.read((char *)&bi,sizeof(BITMAPINFOHEADER)); bi.biSizeImage=m_bmfHeader.bfSize-m_bmfHeader.bfOffBits;//像素数据占用的字节数 int numQuad=0; if(bi.biBitCount<24) { numQuad=1<<bi.biBitCount; } // m_pbi=(BITMAPINFO*)new char[m_bmfHeader.bfOffBits-sizeof(BITMAPFILEHEADER)]; if(!m_pbi.New(0,m_bmfHeader.bfOffBits-sizeof(BITMAPFILEHEADER))) return false; memcpy(m_pbi.GetDataPointer(),&bi,sizeof(BITMAPINFOHEADER)); if(numQuad!=0) { RGBQUAD* quad=(RGBQUAD*)(m_pbi.GetDataPointer()+sizeof(BITMAPINFOHEADER));//调色板指针（若有的话） file.read((char *)quad,sizeof(RGBQUAD)*numQuad); } m_bmpSize.bmpHeight=bi.biHeight; m_bmpSize.bmpWidth=bi.biWidth; m_bmpSize.BitCount=bi.biBitCount; m_bmpSize.BytesPerLine=WIDTHBYTES(m_bmpSize.bmpWidth*m_bmpSize.BitCount); // if(!this->New(m_bmpSize.bmpHeight,m_bmpSize.BytesPerLine))//Rows??Cols??? if(!this->m_pixels.New(0,bi.biSizeImage))//Rows??Cols??????????? {//////////////////////////////////?bi.biSizeImage!=bmpHeight*BytesPerLine????? ////////////////////////注意：彩色图像biSizeImage=2+bmpHeight*BytesPerLine ////////////////////////注意：灰度图像biSizeImage=bmpHeight*BytesPerLine // 内存分配失败，返回NULL。 return false; } file.read(m_pixels.GetDataPointer(), bi.biSizeImage); file.close(); this->m_pFileName=FileName; return true; } bool scBmp::Write(const char *FileName) { if(this->m_bmpSize.bmpHeight==0 || this->m_bmpSize.bmpWidth==0) return false; fstream file; file.open((FileName),ios::binary | ios::out); if(file.fail()) { file.close(); return false; } file.write((char *)&this->GetBmpFileHeader(),sizeof(BITMAPFILEHEADER)); file.write((char *)this->GetBmpInfo(),this->GetBmpFileHeader().bfOffBits-sizeof(BITMAPFILEHEADER)); file.write((char *)this->GetPixels()->GetDataPointer(),this->GetBmpInfo()->bmiHeader.biSizeImage); file.close(); this->m_pFileName=FileName; return true; } void scBmp::Display(HDC hdc,int XDest,int YDest) { if( this->m_pixels.GetLength()==0 || hdc==NULL) return; SetDIBitsToDevice(hdc, XDest, YDest, this->m_bmpSize.bmpWidth, this->m_bmpSize.bmpHeight, 0, 0, 0, m_bmpSize.bmpHeight, this->GetPixels()->GetDataPointer(), this->GetBmpInfo(), DIB_RGB_COLORS); } //void scBmp::MakeDIB(HANDLE hDib) HANDLE scBmp::MakeDIB() { HANDLE hDib=NULL; hDib=::GlobalAlloc(GMEM_MOVEABLE | GMEM_ZEROINIT,m_pbi.GetLength()+m_pixels.GetLength()); char * pDest=(char *)::GlobalLock(HGLOBAL(hDib)); memcpy(pDest,m_pbi.GetDataPointer(),m_pbi.GetLength()); memcpy(pDest+m_pbi.GetLength(),m_pixels.GetDataPointer(),m_pixels.GetLength()); ::GlobalUnlock((HGLOBAL)hDib); //不用释放，系统会管理该内存 return hDib; } bool scBmp::CopyDIB(HANDLE hDib) { if(hDib==NULL) return false; BITMAPINFOHEADER bi; char *pSrc=(char *)::GlobalLock((HGLOBAL)hDib); memcpy(&bi,pSrc,sizeof(BITMAPINFOHEADER)); pSrc+=sizeof(BITMAPINFOHEADER); long BytesPerLine=WIDTHBYTES(bi.biWidth*bi.biBitCount); bi.biSizeImage=BytesPerLine*bi.biHeight; /* if(bi.biBitCount==24) bi.biSizeImage+=2; */ int numQuad=0; if(bi.biBitCount<24) { numQuad=1<<bi.biBitCount; } if(!m_pbi.New(0,sizeof(RGBQUAD)*numQuad+sizeof(BITMAPINFOHEADER))) return false; memcpy(m_pbi.GetDataPointer(),&bi,sizeof(BITMAPINFOHEADER)); if(numQuad!=0) { RGBQUAD* quad=(RGBQUAD*)(m_pbi.GetDataPointer()+sizeof(BITMAPINFOHEADER));//调色板指针（若有的话） memcpy(quad,pSrc,sizeof(RGBQUAD)*numQuad); pSrc+=sizeof(RGBQUAD)*numQuad; } m_bmpSize.bmpHeight=bi.biHeight; m_bmpSize.bmpWidth=bi.biWidth; m_bmpSize.BitCount=bi.biBitCount; m_bmpSize.BytesPerLine=BytesPerLine; //WIDTHBYTES(m_bmpSize.bmpWidth*m_bmpSize.BitCount); if(!this->m_pixels.New(0,bi.biSizeImage))//Rows??Cols??????????? {//////////////////////////////////?bi.biSizeImage!=bmpHeight*BytesPerLine????? ////////////////////////注意：彩色图像biSizeImage=2+bmpHeight*BytesPerLine ////////////////////////注意：灰度图像biSizeImage=bmpHeight*BytesPerLine // 内存分配失败，返回NULL。 return false; } memcpy(this->m_pixels.GetDataPointer(),pSrc,bi.biSizeImage); ::GlobalUnlock((HGLOBAL)hDib); // ::GlobalFree((HGLOBAL)hDib); m_bmfHeader.bfType=0x4d42; m_bmfHeader.bfReserved1=0; m_bmfHeader.bfReserved2=0; m_bmfHeader.bfSize=sizeof(BITMAPFILEHEADER)+m_pbi.GetLength() +m_pixels.GetLength(); m_bmfHeader.bfOffBits=sizeof(BITMAPFILEHEADER)+m_pbi.GetLength(); return true; }