private void SaveThumbnail(Bitmap originBitmap, int width, int height, string directory, string filename, string extension){ var physicalPath = directory + filename + extension; using (var newImage = new Bitmap(width, height)) { using (var graphic = GetGraphic(originBitmap, newImage)) { graphic.DrawImage(originBitmap, 0, 0, width, height); using (var encoderParameters = new EncoderParameters(1)) { encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, 100L); newImage.Save(physicalPath, ImageCodecInfo.GetImageEncoders() .Where(x => x.FilenameExtension.Contains(extension.ToUpperInvariant())) .FirstOrDefault(), encoderParameters); } } } }private Graphics GetGraphic(Image originImage, Bitmap newImage){ newImage.SetResolution(originImage.HorizontalResolution, originImage.VerticalResolution); var graphic = Graphics.FromImage(newImage); graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; graphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; graphic.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality; graphic.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality; return graphic;}