resizeimage.cs

 public static Image ResizeImage(Image initImage, int templateWidth, int templateHeight)
        {
            Image templateImage = null;

            try
            {
                if (initImage.Width <= templateWidth && initImage.Height <= templateHeight)
                    templateImage = initImage;
                else
                {
                    double templateRate = double.Parse(templateWidth.ToString()) / templateHeight;
                    double initRate = double.Parse(initImage.Width.ToString()) / initImage.Height;

                    if (templateRate == initRate)
                    {
                        templateImage = new Bitmap(templateWidth, templateHeight);
                        using (Graphics templateG = Graphics.FromImage(templateImage))
                        {
                            templateG.InterpolationMode = InterpolationMode.High;
                            templateG.SmoothingMode = SmoothingMode.HighQuality;
                            templateG.Clear(Color.White);
                            templateG.DrawImage(initImage, new Rectangle(0, 0, templateWidth, templateHeight), new Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);    
                        }
                    }
                    else
                    {
                        Image pickedImage = null;
                        Graphics pickedG = null;

                        var fromR = new Rectangle(0, 0, 0, 0);
                        var toR = new Rectangle(0, 0, 0, 0);

                        if (templateRate > initRate)
                        {
                            pickedImage = new Bitmap(initImage.Width, int.Parse(Math.Floor(initImage.Width / templateRate).ToString()));
                            pickedG = Graphics.FromImage(pickedImage);

                            fromR.X = 0;
                            fromR.Y = int.Parse(Math.Floor((initImage.Height - initImage.Width / templateRate) / 2).ToString());
                            fromR.Width = initImage.Width;
                            fromR.Height = int.Parse(Math.Floor(initImage.Width / templateRate).ToString());

                            toR.X = 0;
                            toR.Y = 0;
                            toR.Width = initImage.Width;
                            toR.Height = int.Parse(Math.Floor(initImage.Width / templateRate).ToString());
                        }

                        else
                        {
                            pickedImage = new Bitmap(int.Parse(Math.Floor(initImage.Height * templateRate).ToString()), initImage.Height);
                            pickedG = Graphics.FromImage(pickedImage);

                            fromR.X = int.Parse(Math.Floor((initImage.Width - initImage.Height * templateRate) / 2).ToString());
                            fromR.Y = 0;
                            fromR.Width = int.Parse(Math.Floor(initImage.Height * templateRate).ToString());
                            fromR.Height = initImage.Height;

                            toR.X = 0;
                            toR.Y = 0;
                            toR.Width = int.Parse(Math.Floor(initImage.Height * templateRate).ToString());
                            toR.Height = initImage.Height;
                        }

                        pickedG.InterpolationMode = InterpolationMode.HighQualityBicubic;
                        pickedG.SmoothingMode = SmoothingMode.HighQuality;

                        pickedG.DrawImage(initImage, toR, fromR, GraphicsUnit.Pixel);

                        templateImage = new Bitmap(templateWidth, templateHeight);
                        Graphics templateG = Graphics.FromImage(templateImage);
                        templateG.InterpolationMode = InterpolationMode.High;
                        templateG.SmoothingMode = SmoothingMode.HighQuality;
                        templateG.Clear(Color.White);
                        templateG.DrawImage(pickedImage, new Rectangle(0, 0, templateWidth, templateHeight), new Rectangle(0, 0, pickedImage.Width, pickedImage.Height), GraphicsUnit.Pixel);

                        templateG.Dispose();

                        pickedG.Dispose();
                        pickedImage.Dispose();
                    }
                }
            }
            catch (Exception ex)
            {
                Logger.LogMessage("ImageHelper:ResizeImage ex: " + ex.Message);
            }

            return templateImage;
        }