/// <summary>
/// Looks up color values and builds the image from de-compressed RLE8 data.
/// Compresssed RLE8 stream is uncompressed by <see cref="UncompressRle8(int, Span{byte})"/>
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="pixels">The <see cref="PixelAccessor{TPixel}"/> to assign the palette to.</param>
/// <param name="colors">The <see cref="T:byte[]"/> containing the colors.</param>
/// <param name="width">The width of the bitmap.</param>
/// <param name="height">The height of the bitmap.</param>
/// <param name="inverted">Whether the bitmap is inverted.</param>
private void ReadRle8 <TPixel>(PixelAccessor <TPixel> pixels, byte[] colors, int width, int height, bool inverted)
where TPixel : struct, IPixel <TPixel>
{
var color = default(TPixel);
var rgba = new Rgba32(0, 0, 0, 255);
using (var buffer = Buffer2D <byte> .CreateClean(width, height))
{
this.UncompressRle8(width, buffer);
for (int y = 0; y < height; y++)
{
int newY = Invert(y, height, inverted);
Span <byte> bufferRow = buffer.GetRowSpan(y);
Span <TPixel> pixelRow = pixels.GetRowSpan(newY);
for (int x = 0; x < width; x++)
{
rgba.Bgr = Unsafe.As <byte, Bgr24>(ref colors[bufferRow[x] * 4]);
color.PackFromRgba32(rgba);
pixelRow[x] = color;
}
}
}
}
/// <summary>
/// Initializes <see cref="SpectralBlocks"/>
/// </summary>
/// <param name="decoder">The <see cref="OrigJpegDecoderCore"/> instance</param>
public void InitializeDerivedData(OrigJpegDecoderCore decoder)
{
// For 4-component images (either CMYK or YCbCrK), we only support two
// hv vectors: [0x11 0x11 0x11 0x11] and [0x22 0x11 0x11 0x22].
// Theoretically, 4-component JPEG images could mix and match hv values
// but in practice, those two combinations are the only ones in use,
// and it simplifies the applyBlack code below if we can assume that:
// - for CMYK, the C and K channels have full samples, and if the M
// and Y channels subsample, they subsample both horizontally and
// vertically.
// - for YCbCrK, the Y and K channels have full samples.
this.SizeInBlocks = decoder.ImageSizeInMCU.MultiplyBy(this.SamplingFactors);
if (this.Index == 0 || this.Index == 3)
{
this.SubSamplingDivisors = new Size(1, 1);
}
else
{
OrigComponent c0 = decoder.Components[0];
this.SubSamplingDivisors = c0.SamplingFactors.DivideBy(this.SamplingFactors);
}
this.SpectralBlocks = Buffer2D <Block8x8> .CreateClean(this.SizeInBlocks);
}
/// <summary>
/// Initializes a new instance of the <see cref="ImageFrame{TPixel}" /> class.
/// </summary>
/// <param name="width">The width of the image in pixels.</param>
/// <param name="height">The height of the image in pixels.</param>
/// <param name="metaData">The meta data.</param>
internal ImageFrame(int width, int height, ImageFrameMetaData metaData)
{
Guard.MustBeGreaterThan(width, 0, nameof(width));
Guard.MustBeGreaterThan(height, 0, nameof(height));
Guard.NotNull(metaData, nameof(metaData));
this.pixelBuffer = Buffer2D <TPixel> .CreateClean(width, height);
this.MetaData = metaData;
}
#pragma warning restore SA1401
/// <summary>
/// Initializes a new instance of the <see cref="YCbCrImage" /> class.
/// </summary>
/// <param name="width">The width.</param>
/// <param name="height">The height.</param>
/// <param name="ratio">The ratio.</param>
public YCbCrImage(int width, int height, YCbCrSubsampleRatio ratio)
{
Size cSize = CalculateChrominanceSize(width, height, ratio);
this.Ratio = ratio;
this.YStride = width;
this.CStride = cSize.Width;
this.YChannel = Buffer2D <byte> .CreateClean(width, height);
this.CbChannel = Buffer2D <byte> .CreateClean(cSize.Width, cSize.Height);
this.CrChannel = Buffer2D <byte> .CreateClean(cSize.Width, cSize.Height);
}
/// <summary>
/// Initializes a new instance of the <see cref="PixelAccessor{TPixel}"/> class.
/// </summary>
/// <param name="width">The width of the image represented by the pixel buffer.</param>
/// <param name="height">The height of the image represented by the pixel buffer.</param>
public PixelAccessor(int width, int height)
: this(width, height, Buffer2D <TPixel> .CreateClean(width, height), true)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="WeightsBuffer"/> class.
/// </summary>
/// <param name="sourceSize">The size of the source window</param>
/// <param name="destinationSize">The size of the destination window</param>
public WeightsBuffer(int sourceSize, int destinationSize)
{
this.dataBuffer = Buffer2D <float> .CreateClean(sourceSize, destinationSize);
this.Weights = new WeightsWindow[destinationSize];
}