public static Image ResizeImage(Image img, int minsize)
           {
               var size = img.Size;
               if (size.Width >= size.Height)
               {
                   // Could be: if (size.Height < minsize)                  size.Height = minsize;
                   size.Height = minsize;
                   size.Width = (size.Height * img.Width + img.Height - 1) / img.Height;
               }
               else
               {
                   size.Width = minsize;
                   size.Height = (size.Width * img.Height + img.Width - 1) / img.Width;
               }
               return new Bitmap(img, size);
           }

public static byte ResizeImageFile(byte imageFile,int select)
        {
            int width=200, hight=200;
            switch(select)
            {
                case 1:{ width = 200; hight = 200;}break;
                case 2: { width = 410; hight = 200; } break;
                case 3: { width = 410; hight = 410; } break;    
            }
            using (System.Drawing.Image oldImage = System.Drawing.Image.FromStream(new MemoryStream(imageFile)))
            {
                Size newSize = CalculateDimensions(oldImage.Size, width,hight);
                using (Bitmap newImage = new Bitmap(newSize.Width, newSize.Height, PixelFormat.Format24bppRgb))
                {
                    using (Graphics canvas = Graphics.FromImage(newImage))
                    {
                        canvas.SmoothingMode = SmoothingMode.AntiAlias;
                        canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
                        canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
                        canvas.DrawImage(oldImage, new Rectangle(new Point(0, 0), newSize));
                        MemoryStream m = new MemoryStream();
                        newImage.Save(m, ImageFormat.Jpeg);
                        return m.GetBuffer();
                    }
                }
            }
        }
        public static Size CalculateDimensions(Size oldSize, int width, int hight)
        {
            Size newSize = new Size();
            if (oldSize.Height > oldSize.Width)
            {
                newSize.Width = width;
                newSize.Height = hight;
            }
            else
            {
                newSize.Width = width;
                newSize.Height = hight;
            }
            return newSize;
        }