/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x, y) to Rgb24.
/// </summary>
public void Convert(int x, int y, ref RowOctet <TPixel> currentRows)
{
YCbCrForwardConverter <TPixel> .LoadAndStretchEdges(currentRows, this.pixelSpan, new Point(x, y), SampleSize, this.samplingAreaSize);
PixelOperations <TPixel> .Instance.ToRgb24(this.config, this.pixelSpan, this.rgbSpan);
ref Block8x8F redBlock = ref this.R;
/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x,y) placing the result members of the structure (<see cref="Y"/>)
/// </summary>
public void Convert(ImageFrame <TPixel> frame, int x, int y, ref RowOctet <TPixel> currentRows)
{
this.pixelBlock.LoadAndStretchEdges(frame.PixelBuffer, x, y, ref currentRows);
Span <L8> l8Span = this.l8Block.AsSpanUnsafe();
PixelOperations <TPixel> .Instance.ToL8(frame.GetConfiguration(), this.pixelBlock.AsSpanUnsafe(), l8Span);
ref Block8x8F yBlock = ref this.Y;
/// <summary>
/// Encodes the image with no subsampling.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="pixels">The pixel accessor providing access to the image pixels.</param>
/// <param name="cancellationToken">The token to monitor for cancellation.</param>
private void Encode444 <TPixel>(Image <TPixel> pixels, CancellationToken cancellationToken)
where TPixel : unmanaged, IPixel <TPixel>
{
// TODO: Need a JpegScanEncoder<TPixel> class or struct that encapsulates the scan-encoding implementation. (Similar to JpegScanDecoder.)
// (Partially done with YCbCrForwardConverter<TPixel>)
Block8x8F temp1 = default;
Block8x8F temp2 = default;
Block8x8F onStackLuminanceQuantTable = this.luminanceQuantTable;
Block8x8F onStackChrominanceQuantTable = this.chrominanceQuantTable;
var unzig = ZigZag.CreateUnzigTable();
// ReSharper disable once InconsistentNaming
int prevDCY = 0, prevDCCb = 0, prevDCCr = 0;
var pixelConverter = YCbCrForwardConverter <TPixel> .Create();
ImageFrame <TPixel> frame = pixels.Frames.RootFrame;
Buffer2D <TPixel> pixelBuffer = frame.PixelBuffer;
for (int y = 0; y < pixels.Height; y += 8)
{
cancellationToken.ThrowIfCancellationRequested();
var currentRows = new RowOctet <TPixel>(pixelBuffer, y);
for (int x = 0; x < pixels.Width; x += 8)
{
pixelConverter.Convert(frame, x, y, currentRows);
prevDCY = this.WriteBlock(
QuantIndex.Luminance,
prevDCY,
ref pixelConverter.Y,
ref temp1,
ref temp2,
ref onStackLuminanceQuantTable,
ref unzig);
prevDCCb = this.WriteBlock(
QuantIndex.Chrominance,
prevDCCb,
ref pixelConverter.Cb,
ref temp1,
ref temp2,
ref onStackChrominanceQuantTable,
ref unzig);
prevDCCr = this.WriteBlock(
QuantIndex.Chrominance,
prevDCCr,
ref pixelConverter.Cr,
ref temp1,
ref temp2,
ref onStackChrominanceQuantTable,
ref unzig);
}
}
}
/// <summary>
/// Converts a 8x8 image area inside 'pixels' at position (x,y) placing the result members of the structure (<see cref="Y"/>, <see cref="Cb"/>, <see cref="Cr"/>)
/// </summary>
public void Convert(Buffer2D <Pixel> pixelBuffer, int x, int y, ref RowOctet <Pixel> currentRows)
{
this.pixelBlock.LoadAndStretchEdges(pixelBuffer, x, y, ref currentRows);
Span <Rgb24> rgbSpan = this.rgbBlock.AsSpanUnsafe();
this.ToRgb24(this.pixelBlock.AsSpanUnsafe(), this.rgbBlock.AsSpanUnsafe());
ref Block8x8F yBlock = ref this.Y;
public static void LoadAndStretchEdges(RowOctet <TPixel> source, Span <TPixel> dest, Point start, Size sampleSize, Size totalSize)
{
DebugGuard.MustBeBetweenOrEqualTo(start.X, 0, totalSize.Width - 1, nameof(start.X));
DebugGuard.MustBeBetweenOrEqualTo(start.Y, 0, totalSize.Height - 1, nameof(start.Y));
int width = Math.Min(sampleSize.Width, totalSize.Width - start.X);
int height = Math.Min(sampleSize.Height, totalSize.Height - start.Y);
uint byteWidth = (uint)(width * Unsafe.SizeOf <TPixel>());
int remainderXCount = sampleSize.Width - width;
ref byte blockStart = ref MemoryMarshal.GetReference(MemoryMarshal.Cast <TPixel, byte>(dest));
public void Convert(int x, int y, ref RowOctet <TPixel> currentRows, int idx)
{
YCbCrForwardConverter <TPixel> .LoadAndStretchEdges(currentRows, this.pixelSpan, new Point(x, y), SampleSize, this.samplingAreaSize);
PixelOperations <TPixel> .Instance.ToRgb24(this.config, this.pixelSpan, this.rgbSpan);
if (RgbToYCbCrConverterVectorized.IsSupported)
{
RgbToYCbCrConverterVectorized.Convert420(this.rgbSpan, ref this.YLeft, ref this.YRight, ref this.Cb, ref this.Cr, idx);
}
else
{
this.colorTables.Convert420(this.rgbSpan, ref this.YLeft, ref this.YRight, ref this.Cb, ref this.Cr, idx);
}
}
public void LoadAndStretchCorners_FromOrigo <TPixel>(TestImageProvider <TPixel> provider)
where TPixel : unmanaged, IPixel <TPixel>
{
using (Image <TPixel> s = provider.GetImage())
{
var d = default(GenericBlock8x8 <TPixel>);
var rowOctet = new RowOctet <TPixel>(s.GetRootFramePixelBuffer(), 0);
d.LoadAndStretchEdges(s.Frames.RootFrame.PixelBuffer, 0, 0, rowOctet);
TPixel a = s.Frames.RootFrame[0, 0];
TPixel b = d[0, 0];
Assert.Equal(s[0, 0], d[0, 0]);
Assert.Equal(s[1, 0], d[1, 0]);
Assert.Equal(s[7, 0], d[7, 0]);
Assert.Equal(s[0, 1], d[0, 1]);
Assert.Equal(s[1, 1], d[1, 1]);
Assert.Equal(s[7, 0], d[7, 0]);
Assert.Equal(s[0, 7], d[0, 7]);
Assert.Equal(s[7, 7], d[7, 7]);
}
}
public void LoadAndStretchCorners_WithOffset <TPixel>(TestImageProvider <TPixel> provider)
where TPixel : unmanaged, IPixel <TPixel>
{
using (Image <TPixel> s = provider.GetImage())
{
var d = default(GenericBlock8x8 <TPixel>);
RowOctet <TPixel> rowOctet = default;
rowOctet.Update(s.GetRootFramePixelBuffer(), 7);
d.LoadAndStretchEdges(s.Frames.RootFrame.PixelBuffer, 6, 7, ref rowOctet);
Assert.Equal(s[6, 7], d[0, 0]);
Assert.Equal(s[6, 8], d[0, 1]);
Assert.Equal(s[7, 8], d[1, 1]);
Assert.Equal(s[6, 9], d[0, 2]);
Assert.Equal(s[6, 9], d[0, 3]);
Assert.Equal(s[6, 9], d[0, 7]);
Assert.Equal(s[7, 9], d[1, 2]);
Assert.Equal(s[7, 9], d[1, 3]);
Assert.Equal(s[7, 9], d[1, 7]);
Assert.Equal(s[9, 9], d[3, 2]);
Assert.Equal(s[9, 9], d[3, 3]);
Assert.Equal(s[9, 9], d[3, 7]);
Assert.Equal(s[9, 7], d[3, 0]);
Assert.Equal(s[9, 7], d[4, 0]);
Assert.Equal(s[9, 7], d[7, 0]);
Assert.Equal(s[9, 9], d[3, 2]);
Assert.Equal(s[9, 9], d[4, 2]);
Assert.Equal(s[9, 9], d[7, 2]);
Assert.Equal(s[9, 9], d[4, 3]);
Assert.Equal(s[9, 9], d[7, 7]);
}
}