public void SinglePixelOpaque()
{
Configuration config = Configuration.Default;
var quantizer = new WuQuantizer(false);
using (var image = new Image <Rgba32>(config, 1, 1, Rgba32.Black))
using (QuantizedFrame <Rgba32> result = quantizer.CreateFrameQuantizer <Rgba32>(config).QuantizeFrame(image.Frames[0]))
{
Assert.Equal(1, result.Palette.Length);
Assert.Equal(1, result.GetPixelSpan().Length);
Assert.Equal(Rgba32.Black, result.Palette[0]);
Assert.Equal(0, result.GetPixelSpan()[0]);
}
}
/// <inheritdoc />
protected override void OnFrameApply(ImageFrame <TPixel> source, Rectangle sourceRectangle, Configuration configuration)
{
IFrameQuantizer <TPixel> executor = this.Quantizer.CreateFrameQuantizer <TPixel>();
using (QuantizedFrame <TPixel> quantized = executor.QuantizeFrame(source))
{
int paletteCount = quantized.Palette.Length - 1;
// Not parallel to remove "quantized" closure allocation.
// We can operate directly on the source here as we've already read it to get the
// quantized result
for (int y = 0; y < source.Height; y++)
{
Span <TPixel> row = source.GetPixelRowSpan(y);
ReadOnlySpan <byte> quantizedPixelSpan = quantized.GetPixelSpan();
int yy = y * source.Width;
for (int x = 0; x < source.Width; x++)
{
int i = x + yy;
row[x] = quantized.Palette[Math.Min(paletteCount, quantizedPixelSpan[i])];
}
}
}
}
public void SinglePixelOpaque()
{
Configuration config = Configuration.Default;
var quantizer = new WuQuantizer(new QuantizerOptions {
Dither = null
});
using var image = new Image <Rgba32>(config, 1, 1, Color.Black);
ImageFrame <Rgba32> frame = image.Frames.RootFrame;
using IFrameQuantizer <Rgba32> frameQuantizer = quantizer.CreateFrameQuantizer <Rgba32>(config);
using QuantizedFrame <Rgba32> result = frameQuantizer.QuantizeFrame(frame, frame.Bounds());
Assert.Equal(1, result.Palette.Length);
Assert.Equal(1, result.GetPixelSpan().Length);
Assert.Equal(Color.Black, (Color)result.Palette.Span[0]);
Assert.Equal(0, result.GetPixelSpan()[0]);
}
public void SinglePixelTransparent()
{
Configuration config = Configuration.Default;
var quantizer = new WuQuantizer(false);
using (var image = new Image <Rgba32>(config, 1, 1, default(Rgba32)))
using (QuantizedFrame <Rgba32> result = quantizer.CreateFrameQuantizer <Rgba32>(config).QuantizeFrame(image.Frames[0]))
{
Assert.Equal(1, result.Palette.Length);
Assert.Equal(1, result.GetPixelSpan().Length);
Assert.Equal(default, result.Palette[0]);
/// <inheritdoc/>
public virtual QuantizedFrame <TPixel> QuantizeFrame(ImageFrame <TPixel> image)
{
Guard.NotNull(image, nameof(image));
// Get the size of the source image
int height = image.Height;
int width = image.Width;
// Call the FirstPass function if not a single pass algorithm.
// For something like an Octree quantizer, this will run through
// all image pixels, build a data structure, and create a palette.
if (!this.singlePass)
{
this.FirstPass(image, width, height);
}
// Collect the palette. Required before the second pass runs.
TPixel[] palette = this.GetPalette();
this.paletteVector = new Vector4[palette.Length];
PixelOperations <TPixel> .Instance.ToScaledVector4(palette, this.paletteVector, palette.Length);
var quantizedFrame = new QuantizedFrame <TPixel>(image.MemoryAllocator, width, height, palette);
if (this.Dither)
{
// We clone the image as we don't want to alter the original via dithering.
using (ImageFrame <TPixel> clone = image.Clone())
{
this.SecondPass(clone, quantizedFrame.GetPixelSpan(), palette, width, height);
}
}
else
{
this.SecondPass(image, quantizedFrame.GetPixelSpan(), palette, width, height);
}
return(quantizedFrame);
}
public void WuQuantizerYieldsCorrectTransparentPixel <TPixel>(TestImageProvider <TPixel> provider, bool dither)
where TPixel : struct, IPixel <TPixel>
{
using (Image <TPixel> image = provider.GetImage())
{
Assert.True(image[0, 0].Equals(default(TPixel)));
var quantizer = new WuQuantizer(dither);
foreach (ImageFrame <TPixel> frame in image.Frames)
{
QuantizedFrame <TPixel> quantized = quantizer.CreateFrameQuantizer <TPixel>().QuantizeFrame(frame);
int index = this.GetTransparentIndex(quantized);
Assert.Equal(index, quantized.GetPixelSpan()[0]);
}
}
}
/// <summary>
/// Encodes the image to the specified stream from the <see cref="Image{TPixel}"/>.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
/// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
public void Encode <TPixel>(Image <TPixel> image, Stream stream)
where TPixel : struct, IPixel <TPixel>
{
Guard.NotNull(image, nameof(image));
Guard.NotNull(stream, nameof(stream));
this.width = image.Width;
this.height = image.Height;
stream.Write(PngConstants.HeaderBytes, 0, PngConstants.HeaderBytes.Length);
QuantizedFrame <TPixel> quantized = null;
ReadOnlySpan <byte> quantizedPixelsSpan = default;
if (this.pngColorType == PngColorType.Palette)
{
// Create quantized frame returning the palette and set the bit depth.
quantized = this.quantizer.CreateFrameQuantizer <TPixel>().QuantizeFrame(image.Frames.RootFrame);
quantizedPixelsSpan = quantized.GetPixelSpan();
byte bits = (byte)ImageMaths.GetBitsNeededForColorDepth(quantized.Palette.Length).Clamp(1, 8);
// Png only supports in four pixel depths: 1, 2, 4, and 8 bits when using the PLTE chunk
if (bits == 3)
{
bits = 4;
}
else if (bits >= 5 || bits <= 7)
{
bits = 8;
}
this.bitDepth = bits;
}
else
{
this.bitDepth = (byte)(this.use16Bit ? 16 : 8);
}
this.bytesPerPixel = this.CalculateBytesPerPixel();
var header = new PngHeader(
width: image.Width,
height: image.Height,
bitDepth: this.bitDepth,
colorType: this.pngColorType,
compressionMethod: 0, // None
filterMethod: 0,
interlaceMethod: 0); // TODO: Can't write interlaced yet.
this.WriteHeaderChunk(stream, header);
// Collect the indexed pixel data
if (quantized != null)
{
this.WritePaletteChunk(stream, header, quantized);
}
this.WritePhysicalChunk(stream, image);
this.WriteGammaChunk(stream);
this.WriteDataChunks(image.Frames.RootFrame, quantizedPixelsSpan, stream);
this.WriteEndChunk(stream);
stream.Flush();
quantized?.Dispose();
}
/// <summary>
/// Encodes the image to the specified stream from the <see cref="Image{TPixel}"/>.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="image">The <see cref="ImageFrame{TPixel}"/> to encode from.</param>
/// <param name="stream">The <see cref="Stream"/> to encode the image data to.</param>
public void Encode <TPixel>(Image <TPixel> image, Stream stream)
where TPixel : struct, IPixel <TPixel>
{
Guard.NotNull(image, nameof(image));
Guard.NotNull(stream, nameof(stream));
this.width = image.Width;
this.height = image.Height;
// Always take the encoder options over the metadata values.
ImageMetaData metaData = image.MetaData;
PngMetaData pngMetaData = metaData.GetFormatMetaData(PngFormat.Instance);
this.gamma = this.gamma ?? pngMetaData.Gamma;
this.writeGamma = this.gamma > 0;
this.pngColorType = this.pngColorType ?? pngMetaData.ColorType;
this.pngBitDepth = this.pngBitDepth ?? pngMetaData.BitDepth;
this.use16Bit = this.pngBitDepth.Equals(PngBitDepth.Bit16);
stream.Write(PngConstants.HeaderBytes, 0, PngConstants.HeaderBytes.Length);
QuantizedFrame <TPixel> quantized = null;
ReadOnlySpan <byte> quantizedPixelsSpan = default;
if (this.pngColorType == PngColorType.Palette)
{
byte bits;
// Use the metadata to determine what quantization depth to use if no quantizer has been set.
if (this.quantizer == null)
{
bits = (byte)Math.Min(8u, (short)this.pngBitDepth);
int colorSize = ImageMaths.GetColorCountForBitDepth(bits);
this.quantizer = new WuQuantizer(colorSize);
}
// Create quantized frame returning the palette and set the bit depth.
quantized = this.quantizer.CreateFrameQuantizer <TPixel>().QuantizeFrame(image.Frames.RootFrame);
quantizedPixelsSpan = quantized.GetPixelSpan();
bits = (byte)ImageMaths.GetBitsNeededForColorDepth(quantized.Palette.Length).Clamp(1, 8);
// Png only supports in four pixel depths: 1, 2, 4, and 8 bits when using the PLTE chunk
if (bits == 3)
{
bits = 4;
}
else if (bits >= 5 && bits <= 7)
{
bits = 8;
}
this.bitDepth = bits;
}
else
{
this.bitDepth = (byte)(this.use16Bit ? 16 : 8);
}
this.bytesPerPixel = this.CalculateBytesPerPixel();
var header = new PngHeader(
width: image.Width,
height: image.Height,
bitDepth: this.bitDepth,
colorType: this.pngColorType.Value,
compressionMethod: 0, // None
filterMethod: 0,
interlaceMethod: 0); // TODO: Can't write interlaced yet.
this.WriteHeaderChunk(stream, header);
// Collect the indexed pixel data
if (quantized != null)
{
this.WritePaletteChunk(stream, header, quantized);
}
this.WritePhysicalChunk(stream, metaData);
this.WriteGammaChunk(stream);
this.WriteExifChunk(stream, metaData);
this.WriteDataChunks(image.Frames.RootFrame, quantizedPixelsSpan, stream);
this.WriteEndChunk(stream);
stream.Flush();
quantized?.Dispose();
}