Bloom.HtmlThumbNailer.MakeThumbNail C# (CSharp) Method

        private Image MakeThumbNail(Image bmp, ThumbnailOptions options)
        {
            if (bmp == null)
                return null;

            int contentWidth;
            int contentHeight;

            #if !__MonoCS__
            int horizontalOffset = 0;
            int verticalOffset = 0;
            int thumbnailWidth = options.Width;
            int thumbnailHeight = options.Height;
            #endif
            //unfortunately as long as we're using the winform listview, we seem to need to make the icons
            //the same size regardless of the book's shape, otherwise the title-captions don't line up.

            if (options.CenterImageUsingTransparentPadding)
            {
                if (bmp.Width > bmp.Height)//landscape
                {
                    contentWidth = options.Width;
                    contentHeight = (int)(Math.Ceiling(((float)bmp.Height / (float)bmp.Width) * (float)contentWidth));
                }
                else if (bmp.Width < bmp.Height) //portrait
                {
                    contentHeight = options.Height;
                    contentWidth = (int) (Math.Ceiling(((float) bmp.Width/(float) bmp.Height)*(float) contentHeight));
                }
                else //square page
                {
                    contentWidth = options.Width;
                    contentHeight = options.Height;
                }
            #if !__MonoCS__
                horizontalOffset = (options.Width / 2) - (contentWidth / 2);
                verticalOffset = (options.Height / 2) - (contentHeight / 2);
            #endif
            }
            else
            {
                contentHeight = options.Height;
                contentWidth = (int)Math.Floor((float)options.Height * (float)bmp.Width / (float)bmp.Height);
            #if !__MonoCS__
                thumbnailHeight = contentHeight;
                thumbnailWidth = contentWidth;
            #endif
            }

            #if !__MonoCS__
            var thumbnail = new Bitmap(thumbnailWidth, thumbnailHeight, PixelFormat.Format64bppPArgb);
            using (var graphics = Graphics.FromImage(thumbnail))
            {
                graphics.PixelOffsetMode = PixelOffsetMode.None;
                graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;

                var destRect = new Rectangle(horizontalOffset, verticalOffset, contentWidth,contentHeight);

               graphics.DrawImage(bmp,
                        destRect,
                        0,0, bmp.Width, bmp.Height, //source
                        GraphicsUnit.Pixel, WhiteToBackground);

                if (options.BorderStyle != ThumbnailOptions.BorderStyles.None)
                {
                    using (var pn = new Pen(Color.Black, 1))
                    {
                        if (options.BorderStyle == ThumbnailOptions.BorderStyles.Dashed)
                        {
                            pn.DashStyle = DashStyle.Dash;
                            pn.Width = 2;
                        }
                    destRect.Height--; //hack, we were losing the bottom
                        destRect.Width--;
                        graphics.DrawRectangle(pn, destRect);
                    }
                }
            }
            return thumbnail;
            #else
            int skipMarginH = 30;
            int skipMarginV = 30;
            Bitmap croppedImage = (bmp as Bitmap).Clone(new Rectangle(new Point(skipMarginH, skipMarginV),
                new Size(bmp.Width - 2 * skipMarginH, bmp.Height - 2 * skipMarginV)), bmp.PixelFormat);
            return croppedImage.GetThumbnailImage(contentWidth, contentHeight, null, IntPtr.Zero);
            #endif
        }