function PictureSize: TSize;
var
 ResHandle: HWND;
 ResData: HWND;
 BMI: PBitmapInfo;
begin
 Result.cx := 0;
 Result.cy := 0;
 ResHandle := FindResource(HInstance,
  MAKEINTRESOURCE(200), RT_BITMAP);
 if ResHandle <> 0 then
 begin
  ResData := LoadResource(HInstance, ResHandle);
  if ResData <> 0 then
  try
  BMI := LockResource(ResData);
  if Assigned(BMI) then
  try
  Result.cx := BMI.bmiHeader.biWidth;
  Result.cy := BMI.bmiHeader.biHeight;
  // размер картинки вот тут: BMI.bmiHeader.biSizeImage
  finally
  UnlockResource(ResData);
  end;
  finally
  FreeResource(ResData);
  end;
 end;
end;