Convert Bitmap Image to Grayscale

Author: admin | Category: Graphic

//This is how we can convert bitmap to grayscale mode
function ConvertBitmapToGrayscale(const Bitmap: TBitmap): TBitmap;
var
  i, j: Integer;
  Grayshade, Red, Green, Blue: Byte;
  PixelColor: Longint;
begin
  with Bitmap do
    for i := 0 to Width - 1 do
      for j := 0 to Height - 1 do
      begin
        PixelColor := ColorToRGB(Canvas.Pixels[i, j]);
        Red        := PixelColor;
        Green      := PixelColor shr 8;
        Blue       := PixelColor shr 16;
        Grayshade  := Round(0.3 * Red + 0.6 * Green + 0.1 * Blue);
        Canvas.Pixels[i, j] := RGB(Grayshade, Grayshade, Grayshade);
      end;
  Result := Bitmap;
end;
 

Tags: Bitmap, Image