改变位图颜色深度源代码

////////////////////////////////////////////////////////////////////// // // BitmapLib.cpp: Implementation of class CBitmapLib. // // Author: // Gerd Esser // Germany // eMail: admin@gerdesser.de // http://www.gerdesser.de // // History: // 13.09.2000 - Creation // 14.02.2002 - Error correction in GetRGB() case 16 (bit), expand ranges from 32 to 256 // Thanks for comment of "ForJest" // ////////////////////////////////////////////////////////////////////// #include "BitmapLib.h" #ifdef _DEBUG #undef THIS_FILE static char THIS_FILE[]=__FILE__; #define new DEBUG_NEW #endif #define LINES_PER_BAND 100 ////////////////////////////////////////////////////////////////////// // // ////////////////////////////////////////////////////////////////////// CBitmapLib::CBitmapLib() { } ////////////////////////////////////////////////////////////////////// // // ////////////////////////////////////////////////////////////////////// CBitmapLib::~CBitmapLib() { } ////////////////////////////////////////////////////////////////////// // // ////////////////////////////////////////////////////////////////////// int CBitmapLib::GetUsedColors( CString const & stSrcBitmapFile, RGBQUAD * pColorTable, WORD const wMaxColorTableSize, CProgressCtrl * pProgressCtrl ) { ASSERT( pColorTable ); CFile SrcFile; if ( !SrcFile.Open( stSrcBitmapFile, CFile::typeBinary | CFile::modeRead ) ) return FALSE; // init progress control if ( pProgressCtrl ) { pProgressCtrl->SetRange32( 0, SrcFile.GetLength( ) ); pProgressCtrl->SetPos( 0 ); } BITMAPFILEHEADER bmfhSrc; // read bitmapfileheader of source bitmap SrcFile.Read( &bmfhSrc, sizeof( bmfhSrc ) ); if ( pProgressCtrl ) pProgressCtrl->SetPos( SrcFile.GetPosition( ) ); BITMAPINFO * pBmiSrc = ( BITMAPINFO * ) new BYTE[ bmfhSrc.bfOffBits - sizeof( bmfhSrc ) ]; if ( !pBmiSrc ) { SrcFile.Close( ); return blNotEnoughMemory; } // read bitmapinfo header of source bitmap, including the color palette SrcFile.Read( pBmiSrc, bmfhSrc.bfOffBits - sizeof( bmfhSrc ) ); if ( pProgressCtrl ) pProgressCtrl->SetPos( SrcFile.GetPosition( ) ); // only uncompressed bitmaps are possible, because its a bitwise operation if ( pBmiSrc->bmiHeader.biCompression != BI_RGB ) { delete [] pBmiSrc; SrcFile.Close( ); return blUnsupportedCompression; } WORD wUsedColors = 0; UINT uSrcBytesPerLine = pBmiSrc->bmiHeader.biSizeImage / pBmiSrc->bmiHeader.biHeight; // only reserve memory for small bitmap bands, thus working also on fat sized bitmaps BYTE * pBitsSrc = new BYTE[ uSrcBytesPerLine * LINES_PER_BAND ]; // perform each band in a loop for ( UINT i = 0; i < ( UINT ) pBmiSrc->bmiHeader.biHeight; i += LINES_PER_BAND ) { // uCurLines may be smaller at the last loop UINT uCurLines = min( LINES_PER_BAND, pBmiSrc->bmiHeader.biHeight - i ); // read source bitmap data SrcFile.Read( pBitsSrc, uCurLines * uSrcBytesPerLine ); if ( pProgressCtrl ) pProgressCtrl->SetPos( SrcFile.GetPosition( ) ); int nReturn = GetUsedColors( pBmiSrc, pBitsSrc, 0, uCurLines, pColorTable, wMaxColorTableSize, wUsedColors ); if ( nReturn < 0 ) { delete [] pBitsSrc; delete [] pBmiSrc; SrcFile.Close( ); return nReturn; } } delete [] pBitsSrc; delete [] pBmiSrc; SrcFile.Close( ); // reset progress control if ( pProgressCtrl ) pProgressCtrl->SetPos( 0 ); return wUsedColors; } ////////////////////////////////////////////////////////////////////// // // ////////////////////////////////////////////////////////////////////// int CBitmapLib::GetUsedColors( BITMAPINFO const * pBmi, BYTE const * pBits, UINT const nStartScanLine, UINT const nScanLines, RGBQUAD * pColorTable, WORD const wMaxColorTableSize, WORD & wUsedColors ) { ASSERT( pBmi ); ASSERT( pBits ); ASSERT( pColorTable ); BITMAPINFOHEADER const * pBmih = &pBmi->bmiHeader; RGBQUAD rgb; if ( pBmih->biCompression != BI_RGB ) return blUnsupportedCompression; // unsupported bitmap format, no compression for ( UINT i = nStartScanLine; i < nStartScanLine + nScanLines; i++ ) { for ( UINT j = 0; j < ( UINT ) pBmih->biWidth; j++ ) { rgb = GetRGB( pBmi, i, j, pBits ); // search color table for current color for ( WORD k = 0; k < wUsedColors; k++ ) if ( pColorTable[k].rgbBlue == rgb.rgbBlue && pColorTable[k].rgbGreen == rgb.rgbGreen && pColorTable[k].rgbRed == rgb.rgbRed ) break; // if color could not be found if ( k == wUsedColors ) { // table full, no more entries and thus color count possible if ( wUsedColors == wMaxColorTableSize ) return blColorOverflow; // error: color table overflow else { // append new color at color table pColorTable[wUsedColors] = rgb; wUsedColors++; } } } } return wUsedColors; } // CBitmapLib::GetUsedColors( ) ////////////////////////////////////////////////////////////////////// // // ////////////////////////////////////////////////////////////////////// BOOL CBitmapLib::ChangeColorDepth( CString const & stSrcBitmapFile, CString const & stDstBitmapFile, WORD const wDstBitCount, CProgressCtrl * pProgressCtrl ) { ASSERT( stSrcBitmapFile != stDstBitmapFile ); CFile SrcFile; CFile DstFile; if ( !SrcFile.Open( stSrcBitmapFile, CFile::typeBinary | CFile::modeRead ) ) return FALSE; // init progress control if ( pProgressCtrl ) { pProgressCtrl->SetRange32( 0, SrcFile.GetLength( ) ); pProgressCtrl->SetPos( 0 ); } // if bitcount is greater than 8 bits, no device independent bitmap is requested BOOL bDstIsDIB = TRUE; if ( wDstBitCount > 8 ) bDstIsDIB = FALSE; BITMAPFILEHEADER bmfhSrc; // read bitmapfileheader of source bitmap SrcFile.Read( &bmfhSrc, sizeof( bmfhSrc ) ); if ( pProgressCtrl ) pProgressCtrl->SetPos( SrcFile.GetPosition( ) ); BITMAPINFO * pBmiSrc = ( BITMAPINFO * ) new BYTE[ bmfhSrc.bfOffBits - sizeof( bmfhSrc ) ]; if ( !pBmiSrc ) { SrcFile.Close( ); return FALSE; } // read bitmapinfo header of source bitmap, including the color palette SrcFile.Read( pBmiSrc, bmfhSrc.bfOffBits - sizeof( bmfhSrc ) ); if ( pProgressCtrl ) pProgressCtrl->SetPos( SrcFile.GetPosition( ) ); // only uncompressed bitmaps are possible, because its a bitwise operation if ( pBmiSrc->bmiHeader.biCompression != BI_RGB ) { delete [] pBmiSrc; SrcFile.Close( ); return FALSE; } if ( !DstFile.Open( stDstBitmapFile, CFile::typeBinary | CFile::modeCreate | CFile::modeWrite ) ) { delete [] pBmiSrc; SrcFile.Close( ); return FALSE; } BITMAPINFO * pBmiDst; // create destination bitmapinfo header, due to wether it's a DIB or not (with or without color palette) if ( bDstIsDIB ) { pBmiDst = ( BITMAPINFO * ) new BYTE[ sizeof( BITMAPINFOHEADER ) + ( 1 << wDstBitCount ) * sizeof( RGBQUAD ) ]; pBmiDst->bmiHeader = pBmiSrc->bm