GetDibPixel (ImageKit Control/ Effect Method)

This method retrieves the RGB values and palette number of the specified pixel in the Device Independent Bitmap (DIB)

Parameters

Return Value

Returns True if successful, otherwise returns False.

Explanation

The GetDibPixel method retrieves the RGB values and palette number of the specified pixel in the Device Independent Bitmap (DIB). The DibNo parameter value must be the same as that retrieved from the StartDibAccess method. For 1, 4, and 8 bit images, the applicable values are set in the PalNo parameter. For 16, 24, and 32 bit images, the applicable values are set in the Red, Green, and Blue parameters

To access the DIB and manipulate pixel data, you must use the following methods as a group:
StartDibAccess
      |
GetDibPixel, SetDibPixel
      |
EndDibAccess

Note: When accessing the DIB, we recommend you use the ImageKit DLL functions which are faster than this method.

Sample Code
The following code starts access to the DIB, then loops through each pixel in the image, using the GetDibPixel method to retrieve the pixels' rgb values. Then those values are reversed and set using the SetDibPixel method. (For 1, 16, 24, or 32 bit images)

In C++Builder
   bool Ret;
   short DibNo;
   int i, j;
   Byte PalNo, Red, Green, Blue;

   VImageKit1->LayerNo = -1;
   Ret = VImageKit1->GetImageType();
   if (Ret == false) return;
   Ret = VImageKit1->Effect->StartDibAccess(VImageKit1->ImageHandle, DibNo);
   if (Ret == false) return;

   for (i = 0; i < VImageKit1->ImageHeight; i++)
   {
      for (j = 0; j < VImageKit1->ImageWidth; j++)
      {
         Ret = VImageKit1->Effect->GetDibPixel(DibNo, j, i, PalNo, Red, Green, Blue);
         if (VImageKit1->BitCount == 1)
         {
            if (PalNo != 0)
               PalNo = 0;
            else
               PalNo = 1;
         } else if (VImageKit1->BitCount > 8) {
            Blue = 255 - Blue;
            Green = 255 - Green;
            Red = 255 - Red;
         }
         Ret = VImageKit1->Effect->SetDibPixel(DibNo, j, i, PalNo, Red, Green, Blue);
      }
   }
   Ret = VImageKit1->Effect->EndDibAccess(DibNo);

   VImageKit1->Refresh();

In Delphi
   Ret: Boolean;
   DibNo: Smallint;
   i, j: Longint;
   PalNo, Red, Green, Blue: Byte;

   VImageKit1.LayerNo := -1;
   Ret := VImageKit1.GetImageType();
   if Ret = False then Exit;
   Ret := VImageKit1.Effect.StartDibAccess(ImageKit1.ImageHandle, DibNo);
   if Ret = False then Exit;

   for i := 0 to VImageKit1.ImageHeight - 1 do
   begin
      for j := 0 to VImageKit1.ImageWidth - 1 do
      begin
         Ret := VImageKit1.Effect.GetDibPixel(DibNo, j, i, PalNo, Red, Green, Blue);
         if VImageKit1.BitCount = 1 then
         begin
            if PalNo <> 0 then
               PalNo := 0
            else
               PalNo := 1;
         end
         else if VImageKit1.BitCount > 8 then
         begin
            Blue := 255 - Blue;
            Green := 255 - Green;
            Red := 255 - Red;
         end;
         Ret := VImageKit1.Effect.SetDibPixel(DibNo, j, i, PalNo, Red, Green, Blue);
      end;
   end;
   Ret := VImageKit1.Effect.EndDibAccess(DibNo);

   VImageKit1.Refresh;

Differences from the ImageKit 7/8/9 ActiveX

The parameters PalNo, Red, Green, Blue have been changed to type Byte.