/// <summary>
/// Obtain graphic extent
/// </summary>
/// <param name="astream">Stream containing a bitmap or a Jpeg image</param>
/// <param name="extent">Initial bounding box</param>
/// <param name="dpi">Resolution in Dots per inch of the image</param>
/// <returns>Size in twips of the image</returns>
override public Point GraphicExtent(MemoryStream astream, Point extent,
int dpi)
{
int imagesize;
int bitmapwidth, bitmapheight;
bool indexed;
int numcolors, bitsperpixel;
string palette;
bitmapwidth = 0;
bitmapheight = 0;
astream.Seek(0, System.IO.SeekOrigin.Begin);
if (!GraphicUtils.GetJPegInfo(astream, out bitmapwidth, out bitmapheight))
{
bool isgif = false;
astream.Seek(0, System.IO.SeekOrigin.Begin);
GraphicUtils.GetBitmapInfo(astream, out bitmapwidth, out bitmapheight, out imagesize, null,
out indexed, out bitsperpixel, out numcolors, out palette, out isgif);
astream.Seek(0, System.IO.SeekOrigin.Begin);
}
if (dpi <= 0)
{
return(new Point(extent.X, extent.Y));
}
extent.X = (int)Math.Round((double)bitmapwidth / dpi * Twips.TWIPS_PER_INCH);
extent.Y = (int)Math.Round((double)bitmapheight / dpi * Twips.TWIPS_PER_INCH);
return(new Point(extent.X, extent.Y));
}