HOW TO: Resize image and maintain aspect ratio (if needed)

      public static void ResizeAspectRatio(RasterImage img, int canvasWidth, int canvasHeight)
      {
         // image is smaller than the canvas so no need to resize
         if (img.Width < canvasWidth && img.Height < canvasHeight)
            return;

         // Figure out the ratio
         double ratioX = (double)canvasWidth / (double)img.Width;
         double ratioY = (double)canvasHeight / (double)img.Height;
         // use whichever multiplier is smaller
         double ratio = ratioX < ratioY ? ratioX : ratioY;

         // now we can get the new height and width
         int newHeight = Convert.ToInt32(img.Height * ratio);
         int newWidth = Convert.ToInt32(img.Width * ratio);

         //Resize the image
         SizeCommand sizeCommand = new SizeCommand(newWidth, newHeight, RasterSizeFlags.Resample);
         sizeCommand.Run(img);
      }