To resize the image without croping and distorting it. Follow these steps for it:
System.Drawing.Bitmap OriginalBM = new System.Drawing.Bitmap(Server.MapPath("./SiteImages/FoodItems" + "/" + postingImage));
System.Drawing.Size newSize = new System.Drawing.Size(90, 90);
System.Drawing.Bitmap ResizedBM = new System.Drawing.Bitmap(OriginalBM, newSize);
ResizedBM.Save(Server.MapPath("./SiteImages/NewImages/" + postingImage));
