CreateGrayscaleIcon()

Sample Image

SoftechSoftware homepage
SoftechSoftware Email

Environment: VC++ 6.0, XP, Win2k, NT 4.0, Win9x/ME

Abstract

CreateGrayscaleIcon is a Win32 function that creates a grayscale icon starting from a given icon. The resulting icon will have the same size of the original one. This function is written using only Win32 APIs to make possible to be used either in MFC and pure Win32 applications.

Function description

Just add in your project a function like the following:


// This function creates a grayscale icon starting
// from a given icon. The resulting icon will have
// the same size of the original one.
//
// Parameters:
//      [IN]    hIcon
//              Handle to the original icon.
//
// Return value:
//      If the function succeeds, the return value is 
//      the handle to the newly created grayscale icon.
//      If the function fails, the return value is NULL.
//
HICON CreateGrayscaleIcon(HICON hIcon)
{
  HICON       hGrayIcon = NULL;
  HDC         hMainDC = NULL, 
              hMemDC1 = NULL, 
              hMemDC2 = NULL;
  BITMAP      bmp;
  HBITMAP     hOldBmp1 = NULL,
              hOldBmp2 = NULL;
  ICONINFO    csII, csGrayII;
  BOOL        bRetValue = FALSE;

  bRetValue = ::GetIconInfo(hIcon, &csII);
  if (bRetValue == FALSE) return NULL;

  hMainDC = ::GetDC(m_hWnd);
  hMemDC1 = ::CreateCompatibleDC(hMainDC);
  hMemDC2 = ::CreateCompatibleDC(hMainDC);
  if (hMainDC == NULL || 
    hMemDC1 == NULL ||
    hMemDC2 == NULL) 
      return NULL;

  if (::GetObject(csII.hbmColor, 
                sizeof(BITMAP), &
                amp;bmp))
  {
    csGrayII.hbmColor = 
         ::CreateBitmap(csII.xHotspot*2,
                        csII.yHotspot*2, 
                        bmp.bmPlanes, 
                        bmp.bmBitsPixel, 
                        NULL);
    if (csGrayII.hbmColor)
    {
      hOldBmp1 =
         (HBITMAP)::SelectObject(hMemDC1,
                                 csII.hbmColor);
      hOldBmp2 = 
         (HBITMAP)::SelectObject(hMemDC2,
                                 csGrayII.hbmColor);

      ::BitBlt(hMemDC2, 0, 0, csII.xHotspot*2,
               csII.yHotspot*2, hMemDC1, 0, 0,
               SRCCOPY);

      DWORD    dwLoopY = 0, dwLoopX = 0;
      COLORREF crPixel = 0;
      BYTE     byNewPixel = 0;

      for (dwLoopY = 0; dwLoopY < csII.yHotspot*2; dwLoopY++)
      {
        for (dwLoopX = 0; dwLoopX < csII.xHotspot*2; dwLoopX++)
        {
          crPixel = ::GetPixel(hMemDC2, dwLoopX, dwLoopY);

          byNewPixel = (BYTE)((GetRValue(crPixel) * 0.299) +
               (GetGValue(crPixel) * 0.587) +
               (GetBValue(crPixel) * 0.114));
          if (crPixel) ::SetPixel(hMemDC2,
                                  dwLoopX,
                                  dwLoopY,
                                  RGB(byNewPixel,
                                  byNewPixel,
                                  byNewPixel));
        } // for
      } // for

      ::SelectObject(hMemDC1, hOldBmp1);
      ::SelectObject(hMemDC2, hOldBmp2);

      csGrayII.hbmMask = csII.hbmMask;

      csGrayII.fIcon = TRUE;
      hGrayIcon = ::CreateIconIndirect(&csGrayII);
    } // if

    ::DeleteObject(csGrayII.hbmColor);
    //::DeleteObject(csGrayII.hbmMask);
  } // if

  ::DeleteObject(csII.hbmColor);
  ::DeleteObject(csII.hbmMask);
  ::DeleteDC(hMemDC1);
  ::DeleteDC(hMemDC2);
  ::ReleaseDC(m_hWnd, hMainDC);

  return hGrayIcon;
} // End of CreateGrayscaleIcon

  • Date Published: April 23, 2002
    First release (4/16)

Downloads

Download source code & demo project - 123 Kb


Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Protecting business operations means shifting the priorities around availability from disaster recovery to business continuity. Enterprises are shifting their focus from recovery from a disaster to preventing the disaster in the first place. With this change in mindset, disaster recovery is no longer the first line of defense; the organizations with a smarter business continuity practice are less impacted when disasters strike. This SmartSelect will provide insight to help guide your enterprise toward better …

  • Live Event Date: August 20, 2014 @ 1:00 p.m. ET / 10:00 a.m. PT When you look at natural user interfaces as a developer, it isn't just fun and games. There are some very serious, real-world usage models of how things can help make the world a better place – things like Intel® RealSense™ technology. Check out this upcoming eSeminar and join the panel of experts, both from inside and outside of Intel, as they discuss how natural user interfaces will likely be getting adopted in a wide variety …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds