/// <summary>
/// Encodes the image with no chroma, just luminance.
/// </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>
/// <param name="emitBufferBase">The reference to the emit buffer.</param>
private void EncodeGrayscale <TPixel>(Image <TPixel> pixels, CancellationToken cancellationToken, ref byte emitBufferBase)
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;
var unzig = ZigZag.CreateUnzigTable();
// ReSharper disable once InconsistentNaming
int prevDCY = 0;
var pixelConverter = LuminanceForwardConverter <TPixel> .Create();
ImageFrame <TPixel> frame = pixels.Frames.RootFrame;
Buffer2D <TPixel> pixelBuffer = frame.PixelBuffer;
RowOctet <TPixel> currentRows = default;
for (int y = 0; y < pixels.Height; y += 8)
{
cancellationToken.ThrowIfCancellationRequested();
currentRows.Update(pixelBuffer, y);
for (int x = 0; x < pixels.Width; x += 8)
{
pixelConverter.Convert(frame, x, y, ref currentRows);
prevDCY = this.WriteBlock(
QuantIndex.Luminance,
prevDCY,
ref pixelConverter.Y,
ref temp1,
ref temp2,
ref onStackLuminanceQuantTable,
ref unzig,
ref emitBufferBase);
}
}
}
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]);
}
}
public void LoadAndStretchCorners_FromOrigo <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(), 0);
d.LoadAndStretchEdges(s.Frames.RootFrame.PixelBuffer, 0, 0, ref 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]);
}
}