C# Surface.CreateAliasedBitmap方法代碼示例

        public static void Save(Document input, Stream output, Surface scratchSurface, ImageFormat format, ProgressEventHandler callback)
        {
            // flatten the document
            scratchSurface.Clear(ColorBgra.FromBgra(0, 0, 0, 0));

            using (RenderArgs ra = new RenderArgs(scratchSurface))
            {
                input.Render(ra, true);
            }

            using (Bitmap bitmap = scratchSurface.CreateAliasedBitmap())
            {
                LoadProperties(bitmap, input);
                bitmap.Save(output, format);
            }
        }

        protected override void OnSaveT(Document input, Stream output, PropertyBasedSaveConfigToken token, Surface scratchSurface, ProgressEventHandler progressCallback)
        {
            int quality = token.GetProperty<Int32Property>(PropertyNames.Quality).Value;

            ImageCodecInfo icf = GdiPlusFileType.GetImageCodecInfo(ImageFormat.Jpeg);
            EncoderParameters parms = new EncoderParameters(1);
            EncoderParameter parm = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
            parms.Param[0] = parm;

            scratchSurface.Clear(ColorBgra.White);

            using (RenderArgs ra = new RenderArgs(scratchSurface))
            {
                input.Render(ra, false);
            }

            using (Bitmap bitmap = scratchSurface.CreateAliasedBitmap())
            {
                GdiPlusFileType.LoadProperties(bitmap, input);
                bitmap.Save(output, icf, parms);
            }
        }

        protected override void OnSave(Document input, Stream output, SaveConfigToken token, Surface scratchSurface, ProgressEventHandler callback)
        {
            JpegSaveConfigToken jsct = (JpegSaveConfigToken)token;

            ImageCodecInfo icf = GdiPlusFileType.GetImageCodecInfo(ImageFormat.Jpeg);
            EncoderParameters parms = new EncoderParameters(1);
            EncoderParameter parm = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, jsct.Quality); // force '95% quality'
            parms.Param[0] = parm;

            scratchSurface.Clear(ColorBgra.White);

            using (RenderArgs ra = new RenderArgs(scratchSurface))
            {
                input.Render(ra, true);
            }

            using (Bitmap bitmap = scratchSurface.CreateAliasedBitmap())
            {
                GdiPlusFileType.LoadProperties(bitmap, input);
                bitmap.Save(output, icf, parms);
            }
        }

        /// <summary>
        /// Takes a Surface and quantizes it down to an 8-bit bitmap.
        /// </summary>
        /// <param name="quantizeMe">The Surface to quantize.</param>
        /// <param name="ditherAmount">How strong should dithering be applied. 0 for no dithering, 8 for full dithering.</param>
        /// <param name="maxColors">The maximum number of colors to use. This may range from 2 to 255.</param>
        /// <param name="progressCallback">The progress callback delegate.</param>
        /// <returns>An 8-bit Bitmap that is the same size as quantizeMe.</returns>
        protected Bitmap Quantize(Surface quantizeMe, int ditherAmount, int maxColors, ProgressEventHandler progressCallback)
        {
            if (ditherAmount < 0 || ditherAmount > 8)
            {
                throw new ArgumentOutOfRangeException(
                    "ditherAmount",
                    ditherAmount,
                    "Out of bounds. Must be in the range [0, 8]");
            }

            if (maxColors < 2 || maxColors > 255)
            {
                throw new ArgumentOutOfRangeException(
                    "maxColors",
                    maxColors,
                    "Out of bounds. Must be in the range [2, 255]");
            }

            using (Bitmap bitmap = quantizeMe.CreateAliasedBitmap(quantizeMe.Bounds, true))
            {
                OctreeQuantizer quantizer = new OctreeQuantizer(maxColors, 8);
                quantizer.DitherLevel = ditherAmount;
                Bitmap quantized = quantizer.Quantize(bitmap, progressCallback);
                return quantized;
            }
        }

 private static BitmapEx resize(Bitmap bitmap, int width, int height, Rectangle? clipRectangle)
 {
     using (var src = Surface.CopyFromBitmap(bitmap))
     {
         var dest = new Surface(width, height);
         BitmapEx res = new BitmapEx();
         res.surface = dest;
         dest.FitSurface(ResamplingAlgorithm.SuperSampling, src);
         if (clipRectangle == null)
             res.Bitmap = dest.CreateAliasedBitmap();
         else
             res.Bitmap = dest.CreateAliasedBitmap(clipRectangle.Value);
         return res;
     }
 }

        internal override unsafe void FinalSave(
            Document input, 
            Stream output, 
            Surface scratchSurface, 
            int ditherLevel, 
            SavableBitDepths bitDepth, 
            PropertyBasedSaveConfigToken token,
            ProgressEventHandler progressCallback)
        {
            if (bitDepth == SavableBitDepths.Rgba32)
            {
                ImageCodecInfo icf = GdiPlusFileType.GetImageCodecInfo(ImageFormat.Png);
                EncoderParameters parms = new EncoderParameters(1);
                EncoderParameter parm = new EncoderParameter(System.Drawing.Imaging.Encoder.ColorDepth, 32);
                parms.Param[0] = parm;

                using (Bitmap bitmap = scratchSurface.CreateAliasedBitmap())
                {
                    GdiPlusFileType.LoadProperties(bitmap, input);
                    bitmap.Save(output, icf, parms);
                }
            }
            else if (bitDepth == SavableBitDepths.Rgb24)
            {
                // In order to save memory, we 'squish' the 32-bit bitmap down to 24-bit in-place
                // instead of allocating a new bitmap and copying it over.
                SquishSurfaceTo24Bpp(scratchSurface);

                ImageCodecInfo icf = GdiPlusFileType.GetImageCodecInfo(ImageFormat.Png);
                EncoderParameters parms = new EncoderParameters(1);
                EncoderParameter parm = new EncoderParameter(System.Drawing.Imaging.Encoder.ColorDepth, 24);
                parms.Param[0] = parm;

                using (Bitmap bitmap = CreateAliased24BppBitmap(scratchSurface))
                {
                    GdiPlusFileType.LoadProperties(bitmap, input);
                    bitmap.Save(output, icf, parms);
                }
            }
            else if (bitDepth == SavableBitDepths.Rgb8)
            {
                using (Bitmap quantized = Quantize(scratchSurface, ditherLevel, 256, false, progressCallback))
                {
                    ImageCodecInfo icf = GdiPlusFileType.GetImageCodecInfo(ImageFormat.Png);
                    EncoderParameters parms = new EncoderParameters(1);
                    EncoderParameter parm = new EncoderParameter(System.Drawing.Imaging.Encoder.ColorDepth, 8);
                    parms.Param[0] = parm;

                    GdiPlusFileType.LoadProperties(quantized, input);
                    quantized.Save(output, icf, parms);
                }
            }
            else if (bitDepth == SavableBitDepths.Rgba8)
            {
                using (Bitmap quantized = Quantize(scratchSurface, ditherLevel, 256, true, progressCallback))
                {
                    ImageCodecInfo icf = GdiPlusFileType.GetImageCodecInfo(ImageFormat.Png);
                    EncoderParameters parms = new EncoderParameters(1);
                    EncoderParameter parm = new EncoderParameter(System.Drawing.Imaging.Encoder.ColorDepth, 8);
                    parms.Param[0] = parm;

                    GdiPlusFileType.LoadProperties(quantized, input);
                    quantized.Save(output, icf, parms);
                }
            }
            else
            {
                throw new InvalidEnumArgumentException("bitDepth", (int)bitDepth, typeof(SavableBitDepths));
            }
        }

        /// <summary>
        /// Takes a Surface and quantizes it down to an 8-bit bitmap.
        /// </summary>
        /// <param name="quantizeMe">The Surface to quantize.</param>
        /// <param name="ditherAmount">How strong should dithering be applied. 0 for no dithering, 8 for full dithering. 7 is generally a good default to use.</param>
        /// <param name="maxColors">The maximum number of colors to use. This may range from 2 to 256.</param>
        /// <param name="enableTransparency">If true, then one color slot will be reserved for transparency. Any color with an alpha value less than 255 will be transparent in the output.</param>
        /// <param name="progressCallback">The progress callback delegate.</param>
        /// <returns>An 8-bit Bitmap that is the same size as quantizeMe.</returns>
        protected Bitmap Quantize(Surface quantizeMe, int ditherAmount, int maxColors, bool enableTransparency, ProgressEventHandler progressCallback)
        {
            if (ditherAmount < 0 || ditherAmount > 8)
            {
                throw new ArgumentOutOfRangeException(
                    "ditherAmount",
                    ditherAmount,
                    "Out of bounds. Must be in the range [0, 8]");
            }

            if (maxColors < 2 || maxColors > 256)
            {
                throw new ArgumentOutOfRangeException(
                    "maxColors",
                    maxColors,
                    "Out of bounds. Must be in the range [2, 256]");
            }

            // TODO: detect if transparency is needed? or take another argument

            using (Bitmap bitmap = quantizeMe.CreateAliasedBitmap(quantizeMe.Bounds, true))
            {
                OctreeQuantizer quantizer = new OctreeQuantizer(maxColors, enableTransparency);
                quantizer.DitherLevel = ditherAmount;
                Bitmap quantized = quantizer.Quantize(bitmap, progressCallback);
                return quantized;
            }
        }