public void OctreeQuantizerConstructor()
{
var expected = new QuantizerOptions {
MaxColors = 128
};
var quantizer = new OctreeQuantizer(expected);
Assert.Equal(expected.MaxColors, quantizer.Options.MaxColors);
Assert.Equal(QuantizerConstants.DefaultDither, quantizer.Options.Dither);
expected = new QuantizerOptions {
Dither = null
};
quantizer = new OctreeQuantizer(expected);
Assert.Equal(QuantizerConstants.MaxColors, quantizer.Options.MaxColors);
Assert.Null(quantizer.Options.Dither);
expected = new QuantizerOptions {
Dither = KnownDitherings.Atkinson
};
quantizer = new OctreeQuantizer(expected);
Assert.Equal(QuantizerConstants.MaxColors, quantizer.Options.MaxColors);
Assert.Equal(KnownDitherings.Atkinson, quantizer.Options.Dither);
expected = new QuantizerOptions {
Dither = KnownDitherings.Atkinson, MaxColors = 0
};
quantizer = new OctreeQuantizer(expected);
Assert.Equal(QuantizerConstants.MinColors, quantizer.Options.MaxColors);
Assert.Equal(KnownDitherings.Atkinson, quantizer.Options.Dither);
}
private void EncodeLocal <TPixel>(Image <TPixel> image, QuantizedFrame <TPixel> quantized, Stream stream)
where TPixel : unmanaged, IPixel <TPixel>
{
ImageFrame <TPixel> previousFrame = null;
GifFrameMetadata previousMeta = null;
foreach (ImageFrame <TPixel> frame in image.Frames)
{
ImageFrameMetadata metadata = frame.Metadata;
GifFrameMetadata frameMetadata = metadata.GetGifMetadata();
if (quantized is null)
{
// Allow each frame to be encoded at whatever color depth the frame designates if set.
if (previousFrame != null && previousMeta.ColorTableLength != frameMetadata.ColorTableLength &&
frameMetadata.ColorTableLength > 0)
{
var options = new QuantizerOptions
{
Dither = this.quantizer.Options.Dither,
DitherScale = this.quantizer.Options.DitherScale,
MaxColors = frameMetadata.ColorTableLength
};
using (IFrameQuantizer <TPixel> frameQuantizer = this.quantizer.CreateFrameQuantizer <TPixel>(this.configuration, options))
{
quantized = frameQuantizer.QuantizeFrame(frame, frame.Bounds());
}
}
else
{
using (IFrameQuantizer <TPixel> frameQuantizer = this.quantizer.CreateFrameQuantizer <TPixel>(this.configuration))
{
quantized = frameQuantizer.QuantizeFrame(frame, frame.Bounds());
}
}
}
this.bitDepth = ImageMaths.GetBitsNeededForColorDepth(quantized.Palette.Length).Clamp(1, 8);
this.WriteGraphicalControlExtension(frameMetadata, this.GetTransparentIndex(quantized), stream);
this.WriteImageDescriptor(frame, true, stream);
this.WriteColorTable(quantized, stream);
this.WriteImageData(quantized, stream);
quantized?.Dispose();
quantized = null; // So next frame can regenerate it
previousFrame = frame;
previousMeta = frameMetadata;
}
}
// 이미지를 팔레트화시킨다.
// 팔레트에는 반드시 검은색과 흰색은 빠지도록 한다.
static string ExecuteQuantize(string sourceFileName, int maxColor = 30)
{
Logger.WriteLine($"Running {nameof(ExecuteQuantize)}");
var targetFileName = AppendToFileName(sourceFileName, "-Q");
var quOpts = new QuantizerOptions {
MaxColors = maxColor
};
//var quantizer = new OctreeQuantizer(quOpts);
var quantizer = new WuQuantizer(quOpts);
var config = Configuration.Default;
var pixelQuantizer = quantizer.CreatePixelSpecificQuantizer <Rgba32>(config);
using (var image = Image.Load <Rgba32>(sourceFileName))
using (var quantizedResult =
pixelQuantizer.BuildPaletteAndQuantizeFrame(image.Frames[0], image.Frames[0].Bounds()))
{
var quantizedPalette = new List <Color>();
foreach (var p in quantizedResult.Palette.Span)
{
var c = new Color(p);
// 팔레트에 흰색과 검은색은 반드시 빠지도록 한다.
if (c != Color.White && c != Color.Black)
{
quantizedPalette.Add(c);
}
}
using (var stream = new FileStream(targetFileName, FileMode.Create))
{
var encoder = new PngEncoder
{
Quantizer = new PaletteQuantizer(quantizedPalette.ToArray()),
ColorType = PngColorType.Palette
};
image.SaveAsPng(stream, encoder);
stream.Close();
}
return(targetFileName);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="WebSafePaletteQuantizer" /> class.
/// </summary>
/// <param name="options">The quantizer options defining quantization rules.</param>
public WebSafePaletteQuantizer(QuantizerOptions options)
: base(Color.WebSafePalette, options)
{
}
