可以帮我写一段代码，MFC项目用c++语言完成BMP图像处理对数变换

Sure thing! Here’s a code snippet that performs logarithmic transformation on BMP images in an MFC project:

void LogTransform(CBitmap* bmp)
{
    CClientDC dc(AfxGetMainWnd());
    CDC* pDC = &dc;

    CDC MemDC;
    MemDC.CreateCompatibleDC(pDC);
    CBitmap* pOldBitmap = MemDC.SelectObject(bmp);

    BITMAP bitmap;
    bmp->GetBitmap(&bitmap);

    unsigned char* pPixels = (unsigned char*)bitmap.bmBits;
    int w = bitmap.bmWidth;
    int h = bitmap.bmHeight;

    const int c = 255 / log2(256);

    for (int y = 0; y < h; y++) {
        for (int x = 0; x < w; x++) {
            int i = y * bitmap.bmWidthBytes + x * 3;
            unsigned char r = pPixels[i];
            unsigned char g = pPixels[i + 1];
            unsigned char b = pPixels[i + 2];

            r = c * log2(1 + r);
            g = c * log2(1 + g);
            b = c * log2(1 + b);

            pPixels[i] = r;
            pPixels[i + 1] = g;
            pPixels[i + 2] = b;
        }
    }

    MemDC.SelectObject(pOldBitmap);
}

Note that this code assumes that the BMP image is a 24-bit color image. If the image has a different color depth, some adaptations may be needed. Also, keep in mind that this is just a basic example, and more sophisticated algorithms may be needed for more complex image processing tasks.