vc++ 位图转化为 灰度图

//bmp.h



#include "windows.h"
#define IDM_LOADBMP 1
#define IDM_EXIT 2



//bmp.cpp



//////////////////////////////////////////////////////////////
//Name:bmp.c
//Purpose: To open a bitmap file and display it on screen.
//Author: phoenix, CS, TshingHua, Beijing, P.R.C
//Email: bjlufengjun@www.163.net or lufengjun@hotmail.com
//Date:April 3, 1998

//header file
#include "bmp.h"

//macro definition
#define WIDTHBYTES(i) ((i+31)/32*4)

//function declaration
int APIENTRY WinMain (HINSTANCE, HINSTANCE, LPSTR, int);
LRESULT CALLBACK MainWndProc(HWND , UINT,WPARAM, LPARAM);
BOOL LoadBmpFile (HWND hWnd,char *BmpFileName);
BOOL ChangeGray(BYTE *pSrcDib, int width, int height);

//global variable declaration
BITMAPFILEHEADER bf;
BITMAPINFOHEADER bi;
HPALETTE hPalette=NULL;
HBITMAP hBitmap=NULL;
HGLOBAL hImgData=NULL;
HWND hWnd;
///////////////////////////////////////////////////////////
int APIENTRY WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpszCmdLine, int nCmdShow)
{
MSG msg;
WNDCLASS wndclass;

if ( ! hPrevInstance ){
wndclass.style = CS_HREDRAW | CS_VREDRAW;
wndclass.lpfnWndProc = MainWndProc;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hInstance = hInstance;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW);
wndclass.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wndclass.lpszMenuName = "BMPMENU";
wndclass.lpszClassName = "phoenix ip system";
}

if ( ! RegisterClass (&wndclass) )
return FALSE;

hWnd = CreateWindow ("phoenix ip system","Open and display a bitmap",
WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT, NULL,NULL,
hInstance, NULL);
if (!hWnd)
return FALSE;
ShowWindow (hWnd, SW_SHOWMAXIMIZED);
LoadBmpFile(hWnd,"c://test.bmp");
UpdateWindow (hWnd);

while ( GetMessage (&msg, NULL, 0, 0) ){
TranslateMessage (&msg);
DispatchMessage (&msg);
}
return msg.wParam;
}

////////////////////////////////////////////////////////////////
LRESULT CALLBACK MainWndProc(HWND hWnd, UINT message,WPARAM wParam, LPARAM lParam)
{
static HDC hDC,hMemDC;
PAINTSTRUCT ps;

switch (message){
case WM_PAINT:
{
hDC = BeginPaint(hWnd, &ps);
if (hBitmap)
{
hMemDC = CreateCompatibleDC(hDC);
if (hPalette)
{
SelectPalette (hDC, hPalette, FALSE);
SelectPalette (hMemDC, hPalette, FALSE);
RealizePalette (hDC);
}
SelectObject(hMemDC, hBitmap);
BitBlt(hDC, 0, 0, bi.biWidth, bi.biHeight, hMemDC, 0, 0, SRCCOPY);
DeleteDC(hMemDC);
}
EndPaint(hWnd, &ps);
break;
}
case WM_DESTROY: //?????????,?????
if(hBitmap!=NULL)
DeleteObject(hBitmap);

if(hPalette!=NULL)
DeleteObject(hPalette);

if(hImgData!=NULL){
GlobalUnlock(hImgData);
GlobalFree(hImgData);
}
PostQuitMessage (0);
return 0;
case WM_COMMAND:
switch (wParam){
case IDM_LOADBMP:
//加载位图
if(hBitmap!=NULL){
DeleteObject(hBitmap);
hBitmap=NULL;
}
if(hPalette!=NULL){
DeleteObject(hPalette);
hPalette=NULL;
}
if(hImgData!=NULL){
GlobalUnlock(hImgData);
GlobalFree(hImgData);
hImgData=NULL;
}
if(LoadBmpFile(hWnd,"c://test.bmp"))
InvalidateRect(hWnd,NULL,TRUE);
break;
case IDM_EXIT:
SendMessage(hWnd,WM_DESTROY,0,0L);
break;
}
break;
}
return DefWindowProc (hWnd, message, wParam, lParam);
}

////////////////////////////////////////////////////////////////
BOOL LoadBmpFile (HWND hWnd,char *BmpFileName)
{
HFILE hf;
LPBITMAPINFOHEADER lpImgData;
LOGPALETTE *pPal;
LPRGBQUAD lpRGB;
HPALETTE hPrevPalette;
HDC hDc;
HLOCAL hPal;
DWORD LineBytes;
DWORD ImgSize;
DWORD NumColors;
DWORD i;

if((hf=_lopen(BmpFileName,OF_READ))==HFILE_ERROR){
MessageBox(hWnd,"File c://test.bmp not found!","Error Message",MB_OK|MB_ICONEXCLAMATION);
return FALSE;
}
_lread(hf,(LPSTR)&bf,sizeof(BITMAPFILEHEADER));
_lread(hf,(LPSTR)&bi,sizeof(BITMAPINFOHEADER));
LineBytes=(DWORD)WIDTHBYTES(bi.biWidth*bi.biBitCount);
ImgSize=(DWORD)LineBytes*bi.biHeight;
if(bi.biClrUsed!=0)
NumColors=(DWORD)bi.biClrUsed;
else
switch(bi.biBitCount){
case 1:
NumColors=2;
break;
case 4:
NumColors=16;
break;
case 8:
NumColors=256;
break;
case 24:
NumColors=0;
break;
default:
MessageBox(hWnd,"Invalid color numbers!","Error Message",MB_OK|MB_ICONEXCLAMATION);
_lclose(hf);
return FALSE;
}
if(bf.bfOffBits!=(DWORD)(NumColors*sizeof(RGBQUAD)+sizeof(BITMAPFILEHEADER)
+sizeof(BITMAPINFOHEADER)))
{
MessageBox(hWnd,"Invalid color numbers!","Error Message" ,MB_OK|
MB_ICONEXCLAMATION);
_lclose(hf);
return FALSE;
}
bf.bfSize=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+NumColors*sizeof(RGBQUAD)+ImgSize;
if((hImgData=GlobalAlloc(GHND,(DWORD)(sizeof(BITMAPINFOHEADER)+
NumColors*sizeof(RGBQUAD)+ImgSize)))==NULL)
{
MessageBox(hWnd,"Error alloc memory!","ErrorMessage",MB_OK|
MB_ICONEXCLAMATION);
_lclose(hf);
return FALSE;
}

lpImgData=(LPBITMAPINFOHEADER)GlobalLock(hImgData);
_llseek(hf,sizeof(BITMAPFILEHEADER),SEEK_SET);
_hread(hf,(char *)lpImgData,(long)sizeof(BITMAPINFOHEADER)
+(long)NumColors*sizeof(RGBQUAD)+ImgSize);
_lclose(hf);

if(NumColors != 0)
{
hPal=LocalAlloc(LHND,sizeof(LOGPALETTE) + NumColors* sizeof(PALETTEENTRY));
pPal =(LOGPALETTE *)LocalLock(hPal);
pPal->palNumEntries =(WORD) NumColors;
pPal->palVersion = 0x300;
lpRGB = (LPRGBQUAD)((LPSTR)lpImgData + (DWORD)sizeof(BITMAPINFOHEADER));
for (i = 0; i < NumColors; i++) {
pPal->palPalEntry[i].peRed=lpRGB->rgbRed;
pPal->palPalEntry[i].peGreen=lpRGB->rgbGreen;
pPal->palPalEntry[i].peBlue=lpRGB->rgbBlue;
pPal->palPalEntry[i].peFlags=(BYTE)0;
lpRGB++;
}
hPalette=CreatePalette(pPal);
LocalUnlock(hPal);
LocalFree(hPal);
}
hDc=GetDC(hWnd);
if(hPalette){
hPrevPalette=SelectPalette(hDc,hPalette,FALSE);
RealizePalette(hDc);
}

ChangeGray( (BYTE*)((LPSTR)lpImgData+sizeof(BITMAPINFOHEADER) +NumColors*sizeof(RGBQUAD)),
bi.biWidth, bi.biHeight) ;


hBitmap=CreateDIBitmap(hDc, (LPBITMAPINFOHEADER)lpImgData, (LONG)CBM_INIT,
(LPSTR)lpImgData+sizeof(BITMAPINFOHEADER) +NumColors*sizeof(RGBQUAD),
(LPBITMAPINFO)lpImgData, DIB_RGB_COLORS);
if(hPalette && hPrevPalette){
SelectPalette(hDc,hPrevPalette,FALSE);
RealizePalette(hDc);
}

ReleaseDC(hWnd,hDc);
GlobalUnlock(hImgData);
return TRUE;
}

/*---------------------------------------------
pSrcDib 图片数据指针
width 图片橡树宽度
height 图片橡树高度
---------------------------------------------*/
BOOL ChangeGray(BYTE *pSrcDib, int width, int height)
{
BOOL bSuccess=false;
for (register int y=0;y<height;y++)
{
for(register int x=0;x<width;x++)
{
int temp = (BYTE)(0.30*pSrcDib[y*width*3 + x*3] + 0.59*pSrcDib[y*width*3 + x*3 + 1]
+ 0.11*pSrcDib[y*width*3 + x*3 + 2]);

pSrcDib[y*width*3 + x*3] = pSrcDib[y*width*3 + x*3 + 1] = pSrcDib[y*width*3 + x*3 + 2] = temp;
}
}
return bSuccess;

}