This tip show, how to get the filesize, width, height, bitcount and color used 
 from a bitmap. 

 Dieses Beispiel zeigt, wie man Dateigrosse, breite, hohe, Farbtiefe und Farbanzahl 
 von einem Bitmap ausliest. 
}


 procedure TForm1.Button1Click(Sender: TObject);
 var
 fileheader: TBitmapfileheader;
 infoheader: TBitmapinfoheader;
 s: TFilestream;
 begin
 s := TFileStream.Create('c:\YourBitmap.bmp', fmOpenRead);
 try
 s.Read(fileheader, SizeOf(fileheader));
 s.Read(infoheader, SizeOf(infoheader));
 finally
 s.Free;
 end;
 listbox1.Items.Clear;
 listbox1.Items.Add('Filesize: ' + IntToStr(fileheader.bfSize));
 listbox1.Items.Add('Width: ' + IntToStr(infoheader.biWidth));
 listbox1.Items.Add('Height: ' + IntToStr(infoheader.biHeight));
 listbox1.Items.Add('BitCount: ' + IntToStr(infoheader.biBitCount));
 listbox1.Items.Add('Used: ' + IntToStr(infoheader.biClrUsed));
 end;

 { 
 BitCount: 
 1 = black/white 
 4 = 16 colors 
 8 = 256 colors 
}