public void DitherPerformanceTest(bool errorDiffusion)
{
using var bmpRef = Icons.Information.ExtractBitmap(new Size(256, 256));
IQuantizer quantizer = PredefinedColorsQuantizer.SystemDefault8BppPalette();
IDitherer ditherer = errorDiffusion ? (IDitherer)ErrorDiffusionDitherer.FloydSteinberg : OrderedDitherer.Bayer8x8;
new PerformanceTest {
TestName = $"{bmpRef.Width}x{bmpRef.Height}@{bmpRef.GetColorCount()} {(errorDiffusion ? "Error Diffusion" : "Ordered")}", Iterations = 100, CpuAffinity = null
}
.AddCase(() =>
{
using var result = bmpRef.CloneBitmap();
result.Dither(quantizer, ditherer);
}, "BitmapExtensions.Dither")
.AddCase(() =>
{
using var result = bmpRef.CloneBitmap();
using (IBitmapDataInternal bitmapData = BitmapDataFactory.CreateBitmapData(result, ImageLockMode.ReadWrite))
using (IQuantizingSession quantizingSession = quantizer.Initialize(bitmapData))
using (IDitheringSession ditheringSession = ditherer.Initialize(bitmapData, quantizingSession))
{
var row = bitmapData.DoGetRow(0);
int width = bitmapData.Width;
do
{
for (int x = 0; x < width; x++)
{
row.DoSetColor32(x, ditheringSession.GetDitheredColor(row.DoGetColor32(x), x, row.Index));
}
} while (row.MoveNextRow());
}
}, "Sequential dithering")
.DoTest()
.DumpResults(Console.Out);
}
internal void PerformDraw(IQuantizer?quantizer, IDitherer?ditherer)
{
if (quantizer == null)
{
PerformDrawDirect();
return;
}
IReadableBitmapData initSource = SourceRectangle.Size == Source.GetSize()
? Source
: Source.Clip(SourceRectangle);
try
{
Debug.Assert(!quantizer.InitializeReliesOnContent || !Source.HasMultiLevelAlpha(), "This draw performs blending on-the-fly but the used quantizer would require two-pass processing");
context.Progress?.New(DrawingOperation.InitializingQuantizer);
using (IQuantizingSession quantizingSession = quantizer.Initialize(initSource, context))
{
if (context.IsCancellationRequested)
{
return;
}
if (quantizingSession == null)
{
throw new InvalidOperationException(Res.ImagingQuantizerInitializeNull);
}
// quantizing without dithering
if (ditherer == null)
{
PerformDrawWithQuantizer(quantizingSession);
return;
}
// quantizing with dithering
Debug.Assert(!ditherer.InitializeReliesOnContent || !Source.HasMultiLevelAlpha(), "This draw performs blending on-the-fly but the used ditherer would require two-pass processing");
context.Progress?.New(DrawingOperation.InitializingDitherer);
using IDitheringSession ditheringSession = ditherer.Initialize(initSource, quantizingSession, context);
if (context.IsCancellationRequested)
{
return;
}
if (ditheringSession == null)
{
throw new InvalidOperationException(Res.ImagingDithererInitializeNull);
}
PerformDrawWithDithering(quantizingSession, ditheringSession);
}
}
finally
{
if (!ReferenceEquals(initSource, Source))
{
initSource.Dispose();
}
}
}
public void ClearWithDitheringTest(PixelFormat pixelFormat, uint argb, bool errorDiffusion)
{
const int size = 512;
Color color = Color.FromArgb((int)argb);
var ditherer = errorDiffusion ? (IDitherer)ErrorDiffusionDitherer.FloydSteinberg : OrderedDitherer.Bayer8x8;
new PerformanceTest {
TestName = $"{pixelFormat} {size}x{size} {(errorDiffusion ? "Error Diffusion" : "Ordered Dithering")}", Iterations = 10, CpuAffinity = null
}
.AddCase(() =>
{
using var bmp = new Bitmap(size, size, pixelFormat);
using IBitmapDataInternal acc = BitmapDataFactory.CreateBitmapData(bmp, ImageLockMode.ReadWrite);
IQuantizer quantizer = PredefinedColorsQuantizer.FromBitmapData(acc);
var c = new Color32(color);
using (IQuantizingSession quantizingSession = quantizer.Initialize(acc))
using (IDitheringSession ditheringSession = ditherer.Initialize(acc, quantizingSession))
{
IReadWriteBitmapDataRow row = acc.DoGetRow(0);
do
{
for (int x = 0; x < acc.Width; x++)
{
row[x] = ditheringSession.GetDitheredColor(c, x, row.Index);
}
} while (row.MoveNextRow());
}
}, "Sequential clear")
.AddCase(() =>
{
using var bmp = new Bitmap(size, size, pixelFormat);
bmp.Clear(color, ditherer);
}, "BitmapDataAccessor.Clear")
.DoTest()
.DumpResults(Console.Out);
}
private void PerformDrawWithDithering(IQuantizingSession quantizingSession, IDitheringSession ditheringSession)
{
IBitmapDataInternal source = Source;
IBitmapDataInternal target = Target;
Point sourceLocation = SourceRectangle.Location;
Point targetLocation = TargetRectangle.Location;
int sourceWidth = SourceRectangle.Width;
// Sequential processing
if (ditheringSession.IsSequential || SourceRectangle.Width < parallelThreshold >> ditheringScale)
{
context.Progress?.New(DrawingOperation.ProcessingPixels, SourceRectangle.Height);
for (int y = 0; y < SourceRectangle.Height; y++)
{
if (context.IsCancellationRequested)
{
return;
}
ProcessRow(y);
context.Progress?.Increment();
}
return;
}
// Parallel processing
ParallelHelper.For(context, DrawingOperation.ProcessingPixels, 0, SourceRectangle.Height, ProcessRow);
#region Local Methods
void ProcessRow(int y)
{
IDitheringSession session = ditheringSession;
IBitmapDataRowInternal rowSrc = source.DoGetRow(sourceLocation.Y + y);
IBitmapDataRowInternal rowDst = target.DoGetRow(targetLocation.Y + y);
int offsetSrc = sourceLocation.X;
int offsetDst = targetLocation.X;
byte alphaThreshold = quantizingSession.AlphaThreshold;
int width = sourceWidth;
for (int x = 0; x < width; x++)
{
Color32 colorSrc = rowSrc.DoGetColor32(x + offsetSrc);
// fully solid source: overwrite
if (colorSrc.A == Byte.MaxValue)
{
rowDst.DoSetColor32(x + offsetDst, session.GetDitheredColor(colorSrc, x, y));
continue;
}
// fully transparent source: skip
if (colorSrc.A == 0)
{
continue;
}
// source here has a partial transparency: we need to read the target color
int pos = x + offsetDst;
Color32 colorDst = rowDst.DoGetColor32(pos);
// non-transparent target: blending
if (colorDst.A != 0)
{
colorSrc = colorDst.A == Byte.MaxValue
// target pixel is fully solid: simple blending
? colorSrc.BlendWithBackground(colorDst)
// both source and target pixels are partially transparent: complex blending
: colorSrc.BlendWith(colorDst);
}
// overwriting target color only if blended color has high enough alpha
if (colorSrc.A < alphaThreshold)
{
continue;
}
rowDst.DoSetColor32(pos, session.GetDitheredColor(colorSrc, x, y));
}
}
#endregion
}
internal void PerformCopyWithDithering(IQuantizingSession quantizingSession, IDitheringSession ditheringSession, bool skipTransparent)
{
// Sequential processing
if (ditheringSession.IsSequential || SourceRectangle.Width < parallelThreshold >> ditheringScale)
{
context.Progress?.New(DrawingOperation.ProcessingPixels, SourceRectangle.Height);
IBitmapDataRowInternal rowSrc = Source.DoGetRow(SourceRectangle.Y);
IBitmapDataRowInternal rowDst = Target.DoGetRow(TargetRectangle.Y);
byte alphaThreshold = quantizingSession.AlphaThreshold;
for (int y = 0; y < SourceRectangle.Height; y++)
{
if (context.IsCancellationRequested)
{
return;
}
// we can pass x, y to the dithering session because if there is an offset it was initialized by a properly clipped rectangle
for (int x = 0; x < SourceRectangle.Width; x++)
{
Color32 colorSrc = rowSrc.DoGetColor32(x + SourceRectangle.X);
if (skipTransparent && colorSrc.A < alphaThreshold)
{
continue;
}
rowDst.DoSetColor32(x + TargetRectangle.X, ditheringSession.GetDitheredColor(colorSrc, x, y));
}
rowSrc.MoveNextRow();
rowDst.MoveNextRow();
context.Progress?.Increment();
}
return;
}
// Parallel processing
IBitmapDataInternal source = Source;
IBitmapDataInternal target = Target;
Point sourceLocation = SourceRectangle.Location;
Point targetLocation = TargetRectangle.Location;
int sourceWidth = SourceRectangle.Width;
ParallelHelper.For(context, DrawingOperation.ProcessingPixels, 0, SourceRectangle.Height, y =>
{
IDitheringSession session = ditheringSession;
IBitmapDataRowInternal rowSrc = source.DoGetRow(sourceLocation.Y + y);
IBitmapDataRowInternal rowDst = target.DoGetRow(targetLocation.Y + y);
int offsetSrc = sourceLocation.X;
int offsetDst = targetLocation.X;
int width = sourceWidth;
byte alphaThreshold = quantizingSession.AlphaThreshold;
bool skip = skipTransparent;
// we can pass x, y to the dithering session because if there is an offset it was initialized by a properly clipped rectangle
for (int x = 0; x < width; x++)
{
Color32 colorSrc = rowSrc.DoGetColor32(x + offsetSrc);
if (skip && colorSrc.A < alphaThreshold)
{
continue;
}
rowDst.DoSetColor32(x + offsetDst, session.GetDitheredColor(colorSrc, x, y));
}
});
}
