Set image as per the resolution in Inno Setup

Question

I have created a custom welcome page with an image on it, I referred and am using the same code from one of the stack overflow solutions which is perfect for my requirement. But if i set "size of text" to 125% and more in my machine then it will create a gap at the bottom of the inner WizardForm.

PS: my image width and height is 569x320

Script:

[Code]
procedure InitializeWizard;
var
  BitmapFileName: string;
  BitmapImage: TBitmapImage;
  WelcomePage: TWizardPage;
begin
  WelcomePage := CreateCustomPage(wpWelcome, '', '');    

  BitmapFileName := ExpandConstant('{tmp}\DataNova_Logo.bmp');
  ExtractTemporaryFile(ExtractFileName(BitmapFileName));

  BitmapImage := TBitmapImage.Create(WelcomePage);
  BitmapImage.AutoSize := True;
  BitmapImage.Bitmap.LoadFromFile(BitmapFileName);
  BitmapImage.Cursor := crHand;
  BitmapImage.Left := 10;
  BitmapImage.Top := 10;
  BitmapImage.Parent := WelcomePage.Surface;
end;