我有一个C ++ MFC项目，我需要翻转一个可以采用不同格式的位图，然后保存它。我无法使用多种格式保存位图的功能。
当我尝试启用ATL（活动模板库）以使用CImage中的功能时，我添加的#includes打破了项目。在尝试了几件不同的事情后，我放弃了。
由于我无法使用CImage，因此我查看了微软保存位图图像的示例。问题是它们的示例不适用于除24位位图之外的任何图像。
以下是MSDN的功能。
PBITMAPINFO BitmapTools::CreateBitmapInfoStruct(HBITMAP hBmp)
{
BITMAP bmp;
PBITMAPINFO pbmi;
WORD cClrBits;
// Retrieve the bitmap color format, width, and height.
if (!GetObjectW(hBmp, sizeof(BITMAP), (LPSTR)&bmp))
return pbmi;
// errhandler("GetObject", hwnd);
// Convert the color format to a count of bits.
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;
// Allocate memory for the BITMAPINFO structure. (This structure
// contains a BITMAPINFOHEADER structure and an array of RGBQUAD
// data structures.)
if (cClrBits < 24)
{
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,
sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1<< cClrBits));
// There is no RGBQUAD array for these formats: 24-bit-per-pixel or 32-bit-per-pixel
}
else
{
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));
}
// Initialize the fields in the BITMAPINFO structure.
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);
// If the bitmap is not compressed, set the BI_RGB flag.
pbmi->bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color
// indices and store the result in biSizeImage.
// The width must be DWORD aligned unless the bitmap is
// RLE compressed.
pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8
* pbmi->bmiHeader.biHeight;
// Set biClrImportant to 0, indicating that all of the
// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;
return pbmi;
}
创建文件的功能：
void BitmapTools::CreateBMPFile(LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC)
{
HANDLE hf; // file handle
BITMAPFILEHEADER hdr; // bitmap file-header
PBITMAPINFOHEADER pbih; // bitmap info-header
LPBYTE lpBits; // memory pointer
DWORD dwTotal; // total count of bytes
DWORD cb; // incremental count of bytes
BYTE *hp; // byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits)
return;//errhandler("GlobalAlloc", hwnd);
// Retrieve the color table (RGBQUAD array) and the bits
// (array of palette indices) from the DIB.
if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi,
DIB_RGB_COLORS))
{
return;//errhandler("GetDIBits", hwnd);
}
// Create the .BMP file.
hf = CreateFile(pszFile,
GENERIC_READ | GENERIC_WRITE,
(DWORD) 0,
NULL,
CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL,
(HANDLE) NULL);
if (hf == INVALID_HANDLE_VALUE)
return;//errhandler("CreateFile", hwnd);
hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M"
// Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) +
pbih->biSize + pbih->biClrUsed
* sizeof(RGBQUAD) + pbih->biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
// Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) +
pbih->biSize + pbih->biClrUsed
* sizeof (RGBQUAD);
// Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER),
(LPDWORD) &dwTmp, NULL))
{
return;//errhandler("WriteFile", hwnd);
}
// Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER)
+ pbih->biClrUsed * sizeof (RGBQUAD),
(LPDWORD) &dwTmp, ( NULL)))
return;//errhandler("WriteFile", hwnd);
// Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL))
return;// errhandler("WriteFile", hwnd);
// Close the .BMP file.
if (!CloseHandle(hf))
return;// errhandler("CloseHandle", hwnd);
// Free memory.
GlobalFree((HGLOBAL)lpBits);
}
出于某种原因，当有调色板时，最后一个功能不起作用。如果有人有任何修改这个的提示，我会非常感激。
谢谢， -HL
编辑：基本上，第一个函数从已加载的位图中获取并存储BitmapInfo。这是我H文件中声明的函数。为简洁起见，我没有在.cpp文件中发布已经正常工作的所有方法。
class BitmapTools : public CBitmap
{
public:
// PaddedWidth = ((Width * (BitsPerPixel / 8)) + 3) & (~3)
// ScanPadding = PaddedWidth - (Width * ( BitsPerPixel / 8 ));
HBITMAP H_Bitmap;
PBITMAPINFO PBMI;
// If the color depth is 8 bits or lower there will be a color palette/table.
RGBQUAD colortable;
PBITMAPINFO CreateBitmapInfoStruct(HBITMAP hBmp);
void CreateBMPFile(LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC);
bool LoadAttachBitmap(LPCTSTR bmpfile);
void GetWidthAndHeight (int* pw, int* ph) const;
void Invert (BOOL bLateral);
void InvertAndFlip();
};
用于调用方法：
BitmapTools tools;
if (!tools.LoadAttachBitmap("test.bmp"))
{
return;
}
tools.InvertAndFlip();
tools.PBMI = tools.CreateBitmapInfoStruct(tools.H_Bitmap);
HDC dc = CreateCompatibleDC(NULL);
tools.CreateBMPFile("temp.bmp", tools.PBMI, tools.H_Bitmap, dc);
return;
答案 0 :(得分：1)
我认为调色板图像存在内存分配问题，而且标题数据存在错误。这应该工作：
BOOL SaveHBitmap(const char* filename, HBITMAP hbitmap, HDC hdc)
{
BITMAP bitmap;
if (!GetObject(hbitmap, sizeof(BITMAP), (void*)&bitmap))
return FALSE;
// Convert the color format to a count of bits.
WORD clrbits = (WORD)(bitmap.bmPlanes * bitmap.bmBitsPixel);
if (clrbits == 1) clrbits = 1;
else if (clrbits <= 4) clrbits = 4;
else if (clrbits <= 8) clrbits = 8;
else if (clrbits <= 16) clrbits = 16;
else if (clrbits <= 24) clrbits = 24;
else clrbits = 32;
//clrUsed is zero for 24 bit and higher
int clrUsed = (clrbits <= 8) ? (1 << clrbits) : 0;
TRACE("clrUsed %d\n", clrUsed);
int bitmapInfoSize = sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * clrUsed;
PBITMAPINFO bitmapInfo = (PBITMAPINFO)new char[bitmapInfoSize];
memset(bitmapInfo, 0, bitmapInfoSize);
// Initialize the fields in the BITMAPINFO structure.
bitmapInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bitmapInfo->bmiHeader.biWidth = bitmap.bmWidth;
bitmapInfo->bmiHeader.biHeight = bitmap.bmHeight;
bitmapInfo->bmiHeader.biPlanes = bitmap.bmPlanes;
bitmapInfo->bmiHeader.biBitCount = bitmap.bmBitsPixel;
bitmapInfo->bmiHeader.biClrUsed = clrUsed;
bitmapInfo->bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color indices and store the result in biSizeImage.
// The width must be DWORD aligned unless the bitmap is RLE compressed.
int dibSize = ((bitmap.bmWidth * clrbits + 31) & ~31) / 8 * bitmap.bmHeight;
char* dib = new char[dibSize];
bitmapInfo->bmiHeader.biSizeImage = dibSize;
// Set biClrImportant to 0, indicating that all of the device colors are important.
bitmapInfo->bmiHeader.biClrImportant = 0;
PBITMAPINFOHEADER bmpInfoHeader = (PBITMAPINFOHEADER)bitmapInfo;
if (!GetDIBits(hdc, hbitmap, 0, bmpInfoHeader->biHeight, dib, bitmapInfo, 0))
{
delete bitmapInfo;
delete[]dib;
return FALSE;
}
BITMAPFILEHEADER bmpFileHeader = { 0 };
bmpFileHeader.bfType = 0x4d42;
bmpFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + clrUsed * sizeof(RGBQUAD);
bmpFileHeader.bfSize = bmpFileHeader.bfOffBits + dibSize;
HANDLE hfile = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (hfile != INVALID_HANDLE_VALUE)
{
DWORD dwTmp;
WriteFile(hfile, (void*)&bmpFileHeader, sizeof(BITMAPFILEHEADER), &dwTmp, NULL);
WriteFile(hfile, (void*)bmpInfoHeader, sizeof(BITMAPINFOHEADER) + clrUsed * sizeof(RGBQUAD), &dwTmp, NULL);
WriteFile(hfile, (void*)dib, dibSize, &dwTmp, NULL);
CloseHandle(hfile);
}
delete bitmapInfo;
delete[]dib;
return TRUE;
}
void foo()
{
const char* filename = "c:\\test\\test8bit.bmp";
if (IDOK != ::MessageBox(0, "this will over-write the file", 0, MB_OKCANCEL))
return;
HBITMAP hbitmap = (HBITMAP)LoadImage(0, filename, IMAGE_BITMAP, 0, 0,
LR_CREATEDIBSECTION | LR_DEFAULTSIZE | LR_LOADFROMFILE);
if (!hbitmap) return;
//modify hbitmap here
//...
HDC hdc = CreateCompatibleDC(0);
SaveHBitmap(filename, hbitmap, hdc);
DeleteDC(hdc);
ShellExecute(0, 0, filename, 0, 0, SW_SHOW);
}