请帮助我将位图转换为灰度 [英] Please help me converting bitmap to greyscale

问题描述

我正在使用MFC将位图图像转换为灰度图像，但得到了一些错误帮助.这是我的代码:

I''m converting a bitmap image into grey scale using MFC but got some errors kindly help. Here is my code:

void CFingerprintSystem_FASSDlg::OnNormalization()
{
// TODO: Add your control notification handler code here

CString m_sBitmap;

HBITMAP hGrayBitmap = (HBITMAP) ::LoadImage(AfxGetInstanceHandle(),
m_sBitmap, IMAGE_BITMAP, 100,140, LR_LOADFROMFILE |
LR_CREATEDIBSECTION);

BITMAP bm;

GetObject(hGrayBitmap, sizeof(BITMAP), (LPSTR)&bm);

typedef struct tagBITMAP
{
LONG bmType;
LONG bmWidth;
LONG bmHeight;
LONG bmWidthBytes;
WORD bmPlanes;
WORD bmBitsPixel;
LPVOID bmBits;
}
BITMAP, *PBITMAP;


if (hGrayBitmap)
{
CStatic *pImg = (CStatic*)GetDlgItem(IDC_STATIC_Processed);
BYTE * pImgByte = (BYTE *) bm.bmBits;



if(pImg==NULL)
{
AfxMessageBox("Fail to convert grayscale");
}
else
{

INT iWidthBytes = bm.bmWidth * 3;

for ( int y = 0; y < bm.bmHeight; y++)
{
for ( int x = 0; x < bm.bmWidth*3; x++)
{

unsigned char R = pImgByte[y*iWidthBytes+x+2];
unsigned char G = pImgByte[y*iWidthBytes+x+1];
unsigned char B = pImgByte[y*iWidthBytes+x];;

INT gray = ceil(0.3*R + 0.59*G + 0.11*B);

pImgByte[y*iWidthBytes+x+2] = gray;
pImgByte[y*iWidthBytes+x+1] = gray;
pImgByte[y*iWidthBytes+x] = gray;
}
}

pImg->SetBitmap(hGrayBitmap);

}
}
}

有错误

There are errors

error C2665: ''AfxMessageBox'' : none of the 2 overloads could convert all the argument types
        d:\visual studio\vc\atlmfc\include\afxwin.h(5372): could be ''int AfxMessageBox(LPCTSTR,UINT,UINT)''
        d:\visual studio\vc\atlmfc\include\afxwin.h(5374): or       ''int AfxMessageBox(UINT,UINT,UINT)''
        while trying to match the argument list ''(const char [26])''

推荐答案

尝试以下操作:

Try this:

void CdrawbitmapDlg::OnBnClickedButton1()
{
   CBitmap img;
   CDC dc;
   BITMAP bmp;
   img.LoadBitmapW(IDB_BITMAP1);
   img.GetBitmap(&bmp);
   CDC* pDC = this->GetDC();
   dc.CreateCompatibleDC(pDC);
   CBitmap* pOld = dc.SelectObject(&img);
   for(int y = 0; y < bmp.bmHeight; y++)
   {
      for(int x = 0; x < bmp.bmWidth; x++)
      {
         COLORREF rgb = dc.GetPixel(x, y);
         BYTE r = GetRValue(rgb);
         BYTE g = GetGValue(rgb);
         BYTE b = GetBValue(rgb);
         BYTE bw = (BYTE)(0.3 * r + 0.59 * g + 0.11 * b + 0.5);
         dc.SetPixel(x, y, RGB(bw, bw, bw));
      }
   }
   pDC->BitBlt(100, 100, bmp.bmWidth, bmp.bmHeight, &dc, 0, 0, SRCCOPY);
   dc.SelectObject(pOld);
}

您正在向AfxMessageBox函数传递 ANSI 字符串，但是该函数需要 ANSI 或 UNICODE 字符串，具体取决于您的项目设置.

只需更改行:

You are passing an ANSI string to he AfxMessageBox function, but that function require an ANSI or UNICODE string depending on your project settings.

Simply change the line:

AfxMessageBox("Fail to convert grayscale");

至:

to:

AfxMessageBox(_T("Fail to convert grayscale"));

请注意，宏_T(x)获取一个字符串，如果您的项目使用 MBCS字符集，则不修改该字符串，否则，如果您的项目使用 UNICODE字符集，则宏会添加一个L在表示宽字符字符串

Note that the macro _T(x) gets a string and, if your project use the MBCS charset lets the string unmodified otherwise, if your project use the UNICODE charset the macro add a L before the string (e.g. L"my string") that means wide-char string

error C3861: ''ceil'': identifier not found->的字符串(例如L"my string")之前.将#include <math.h>添加到stdafx.h或.cpp文件的顶部
error C2065: ''IDC_STATIC_Processed'': undeclared identifier->确保标识符正确，在.cpp文件顶部添加#include "resource.h"

error C3861: ''ceil'': identifier not found --> add #include <math.h> into your stdafx.h or on top of your .cpp file
error C2065: ''IDC_STATIC_Processed'': undeclared identifier --> ensure that the identifier is correct, add #include "resource.h" on top of your .cpp file

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