谁有一个将jpg格式的文件转换为bmp格式文件的程序

[grasshopperliu]

各位大虾：
我需要一个将jpg格式的文件转换为bmp格式文件的程序，
要原代码。谢了先

[howtotell]

一个迂回的方法：把jpg显示到窗口，然后再截图。jpg和截图的代码csdn以前的帖子都有。如果找不到可以发信息给我。

[xtmzl]

网上有这方面的控件。

[shines77]

CxImage类或者Intel的IJL库

[shines77]

http://www.codeproject.com/bitmap/cximage.asp

[bcpl]

下面的JpgToBmp函数可以实现，为清晰起见，去掉了所有错误处理，真正要用的话
要自己加上..

PBITMAPINFO CreateBitmapInfoStruct(HBITMAP hBmp)
{
BITMAP bmp;
PBITMAPINFO pbmi;
WORD cClrBits;

GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp);

cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;
else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;

if (cClrBits != 24)
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1<< cClrBits));
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));

pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
pbmi->bmiHeader.biClrUsed = (1<<cClrBits);

pbmi->bmiHeader.biCompression = BI_RGB;

pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31)
& ~31) /8 * pbmi->bmiHeader.biHeight;
pbmi->bmiHeader.biClrImportant = 0;
return pbmi;
}

void CreateBMPFile(LPCTSTR pszFile, PBITMAPINFO pbi,
HBITMAP hBMP, HDC hDC)
{
HANDLE hf;
BITMAPFILEHEADER hdr;
PBITMAPINFOHEADER pbih;
LPBYTE lpBits;
DWORD dwTotal;
DWORD cb;
BYTE *hp;
DWORD dwTmp;

pbih = (PBITMAPINFOHEADER) pbi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);

GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, DIB_RGB_COLORS);

hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, (DWORD) 0, NULL,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL);
hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M"
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize +
pbih->biClrUsed * sizeof(RGBQUAD) + pbih->biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;

hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize +
pbih->biClrUsed * sizeof (RGBQUAD);

WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL);

WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER)
+ pbih->biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL));

dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL);

CloseHandle(hf);
GlobalFree((HGLOBAL)lpBits);
}

void JpgToBmp(LPCTSTR lpszJpgFile, LPCTSTR lpszBmpFile)
{
HANDLE hFile = CreateFile(lpszJpgFile, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
DWORD dwFileSize = GetFileSize(hFile, NULL);
LPVOID pvData = NULL;
HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, dwFileSize);
pvData = GlobalLock(hGlobal);
DWORD dwBytesRead = 0;
BOOL bRead = ReadFile(hFile, pvData, dwFileSize, &dwBytesRead, NULL);
GlobalUnlock(hGlobal);
CloseHandle(hFile);
LPSTREAM pstm = NULL;
HRESULT hr = CreateStreamOnHGlobal(hGlobal, TRUE, &pstm);
LPPICTURE pPicture;
hr = ::OleLoadPicture(pstm, dwFileSize, FALSE, IID_IPicture, (LPVOID *)&pPicture);
pstm->Release();

HDC hdc = ::CreateCompatibleDC(NULL); //::GetDC(m_hWnd);
HDC hdcOld;
HBITMAP hBitmap;
HBITMAP hOldBitmap;

pPicture->SelectPicture(hdc, &hdcOld, (OLE_HANDLE*)&hOldBitmap);
pPicture->get_Handle((OLE_HANDLE*)&hBitmap);

PBITMAPINFO pbi = CreateBitmapInfoStruct(hBitmap);
CreateBMPFile(lpszBmpFile, pbi, hBitmap, hdc);

pPicture->SelectPicture(hdcOld, NULL, NULL);
::SelectObject(hdc, hOldBitmap);
::DeleteDC(hdc);
}

[bsbcn]

我也需要这方面的东西。，谢谢
了