Darken Image (Degrade)

Question

Is it possible to darken an image inside a Timage in Delphi ??? Is there a component, something like that to do it ? The Program puts the image, and I need to darken right after it is inserted...

Answer 1

Guy you can convert to bitmap and scroll the pixel array pixel by pixel by changing the value of in RGB proportionally, can even exist a component but I do not know and other that the installation of many components is not cool, projects can be discontinued and some methods you can migrate from version to version.

    function  TForm1.GrayScale (Imagem : TBitmap) : TBitmap;
    var Gray : TBitmap;
    i, j : Integer;
    Pixel : TColor;
    GrayScale : Integer;
    Red, Green, Blue : Double;
    begin
      Gray        := TBitmap.Create;
      Gray.Height := Imagem.Height;
      Gray.Width  := Imagem.Width;

      for i := 0 to Imagem.Height do
      begin
        for j := 0 to Imagem.Width do
        begin
          Pixel := Imagem.Canvas.Pixels[j,i];

          Red   := GetRValue(Pixel);
          Green := GetGValue(Pixel);
          Blue  := GetBValue(Pixel);

          GrayScale := Trunc((Red * 0.3) + (Green * 0.59) + (Blue * 0.0011));
          Gray.Canvas.Pixels[j,i] := RGB(Byte(GrayScale), Byte(GrayScale),          Byte(GrayScale));
            end;
        end;
           Result := Gray;
        end;

This Example code switches to grayscale to get to the key you want you can change the values that multiply the RGB.