/// <summary>
/// Gets scaling dimensions.
/// </summary>
/// <param name="width"></param>
/// <param name="maxWidth"></param>
/// <param name="height"></param>
/// <param name="maxHeight"></param>
/// <returns></returns>
private static ScaleDimensionHelper GetScaleDimensions(int width, int maxWidth, int height, int maxHeight)
{
ScaleDimensionHelper s = new ScaleDimensionHelper();
// width
if (width <= maxWidth)
{
s.NewWidth = width;
s.NewHeight = height;
}
else
{
s.NewWidth = maxWidth;
s.ScaleFactor = s.NewWidth / (double)width;
s.NewHeight = (int)(height * s.ScaleFactor);
}
// height
if (maxHeight <= 0 || s.NewHeight <= maxHeight)
{
return(s);
}
s.ScaleFactor = maxHeight / (double)s.NewHeight;
s.NewHeight = maxHeight;
s.NewWidth = (int)(s.NewWidth * s.ScaleFactor);
return(s);
}
/// <summary>
/// Resizes an image.
/// Make sure that if you're pulling the source image from a stream,
/// the stream remains open.
/// </summary>
/// <param name="img"></param>
/// <param name="maxWidth"></param>
/// <param name="maxHeight"></param>
/// <returns></returns>
public static byte[] ResizeImage(Image img, int maxWidth, int maxHeight = 0)
{
ScaleDimensionHelper s = GetScaleDimensions(img.Width, maxWidth, img.Height, maxHeight);
Rectangle imgRect = CreateRectangleFromDimensions(s);
Bitmap bmp = CreateBitmapFromDimensions(s.NewWidth, s.NewHeight);
DrawResizeOntoBitmap(bmp, img, imgRect);
byte[] imgBytes = GetImageBytes(bmp, img.RawFormat);
return(imgBytes);
}
private static Rectangle CreateRectangleFromDimensions(ScaleDimensionHelper s)
{
Rectangle area = new Rectangle(0, 0, s.NewWidth, s.NewHeight);
return(area);
}
