Schwarzanteil eines TImage ermitteln

[Landfloh]

Bei mir bleibt der Wert auf Null.

Quellcode:

Delphi-Quellcode:

procedure TForm1.Button1Click(Sender: TObject);
var
  i,j : Integer;
  blackCount: Integer;
begin
  blackCount := 0;
  for i:= 0 to image1.Picture.Bitmap.Height -1 do
    for j:=0 to image1.Picture.Bitmap.Width -1 do
     if image1.Picture.Bitmap.Canvas.Pixels[j,i] = clBlack then
       inc(blackCount);
       Label1.Caption := '';
       Label1.Caption := (IntToStr(blackCount));
end;