public void CorrectGamma(Single gamma, IColorQuantizer quantizer, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(quantizer, "quantizer");
// determines which method of color retrieval to use
IList <Point> path = quantizer.GetPointPath(Width, Height);
// calculates gamma ramp
Int32[] gammaRamp = new Int32[256];
for (Int32 index = 0; index < 256; ++index)
{
gammaRamp[index] = Clamp((Int32)((255.0f * Math.Pow(index / 255.0f, 1.0f / gamma)) + 0.5f));
}
// use different scanning method depending whether the image format is indexed
ProcessPixelFunction correctGamma = pixel =>
{
Color oldColor = GetColorFromPixel(pixel);
Int32 red = gammaRamp[oldColor.R];
Int32 green = gammaRamp[oldColor.G];
Int32 blue = gammaRamp[oldColor.B];
Color newColor = Color.FromArgb(red, green, blue);
SetColorToPixel(pixel, newColor, quantizer);
return(true);
};
// performs the image scan, using a chosen method
ProcessPerPixel(path, correctGamma, parallelTaskCount);
}
public void ScanColors(IColorQuantizer quantizer, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(quantizer, "quantizer");
// determines which method of color retrieval to use
IList <Point> path = quantizer.GetPointPath(Width, Height);
// use different scanning method depending whether the image format is indexed
ProcessPixelFunction scanColors = pixel =>
{
quantizer.AddColor(GetColorFromPixel(pixel), pixel.X, pixel.Y);
return(false);
};
// performs the image scan, using a chosen method
ProcessPerPixel(path, scanColors, parallelTaskCount);
}
public void ScanColors(IColorQuantizer quantizer, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(quantizer, "quantizer");
// determines which method of color retrieval to use
IList<Point> path = quantizer.GetPointPath(Width, Height);
// use different scanning method depending whether the image format is indexed
ProcessPixelFunction scanColors = pixel =>
{
quantizer.AddColor(GetColorFromPixel(pixel), pixel.X, pixel.Y);
return false;
};
// performs the image scan, using a chosen method
ProcessPerPixel(path, scanColors, parallelTaskCount);
}
public void Quantize(ImageBuffer target, IColorQuantizer quantizer, IColorDitherer ditherer, Int32 colorCount, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(target, "target");
Guard.CheckNull(quantizer, "quantizer");
// initializes quantization parameters
Boolean isTargetIndexed = target.PixelFormat.IsIndexed();
// step 1 - prepares the palettes
List<Color> targetPalette = isTargetIndexed ? SynthetizePalette(quantizer, colorCount, parallelTaskCount) : null;
// step 2 - updates the bitmap palette
target.bitmap.SetPalette(targetPalette);
target.UpdatePalette(true);
// step 3 - prepares ditherer (optional)
if (ditherer != null) ditherer.Prepare(quantizer, colorCount, this, target);
// step 4 - prepares the quantization function
TransformPixelFunction quantize = (sourcePixel, targetPixel) =>
{
// reads the pixel color
Color color = GetColorFromPixel(sourcePixel);
// converts alpha to solid color
color = QuantizationHelper.ConvertAlpha(color);
// quantizes the pixel
SetColorToPixel(targetPixel, color, quantizer);
// marks pixel as processed by default
Boolean result = true;
// preforms inplace dithering (optional)
if (ditherer != null && ditherer.IsInplace)
{
result = ditherer.ProcessPixel(sourcePixel, targetPixel);
}
// returns the result
return result;
};
// step 5 - generates the target image
IList<Point> path = quantizer.GetPointPath(Width, Height);
TransformPerPixel(target, path, quantize, parallelTaskCount);
// step 6 - preforms non-inplace dithering (optional)
if (ditherer != null && !ditherer.IsInplace)
{
Dither(target, ditherer, quantizer, colorCount, 1);
}
// step 7 - finishes the dithering (optional)
if (ditherer != null) ditherer.Finish();
// step 8 - clean-up
quantizer.Finish();
}
public void CorrectGamma(Single gamma, IColorQuantizer quantizer, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(quantizer, "quantizer");
// determines which method of color retrieval to use
IList<Point> path = quantizer.GetPointPath(Width, Height);
// calculates gamma ramp
Int32[] gammaRamp = new Int32[256];
for (Int32 index = 0; index < 256; ++index)
{
gammaRamp[index] = Clamp((Int32) ((255.0f*Math.Pow(index/255.0f, 1.0f/gamma)) + 0.5f));
}
// use different scanning method depending whether the image format is indexed
ProcessPixelFunction correctGamma = pixel =>
{
Color oldColor = GetColorFromPixel(pixel);
Int32 red = gammaRamp[oldColor.R];
Int32 green = gammaRamp[oldColor.G];
Int32 blue = gammaRamp[oldColor.B];
Color newColor = Color.FromArgb(red, green, blue);
SetColorToPixel(pixel, newColor, quantizer);
return true;
};
// performs the image scan, using a chosen method
ProcessPerPixel(path, correctGamma, parallelTaskCount);
}
public void Quantize(ImageBuffer target, IColorQuantizer quantizer, IColorDitherer ditherer, Int32 colorCount, Int32 parallelTaskCount = 4)
{
// checks parameters
Guard.CheckNull(target, "target");
Guard.CheckNull(quantizer, "quantizer");
// initializes quantization parameters
Boolean isTargetIndexed = target.PixelFormat.IsIndexed();
// step 1 - prepares the palettes
List <Color> targetPalette = isTargetIndexed ? SynthetizePalette(quantizer, colorCount, parallelTaskCount) : null;
// step 2 - updates the bitmap palette
target.bitmap.SetPalette(targetPalette);
target.UpdatePalette(true);
// step 3 - prepares ditherer (optional)
if (ditherer != null)
{
ditherer.Prepare(quantizer, colorCount, this, target);
}
// step 4 - prepares the quantization function
TransformPixelFunction quantize = (sourcePixel, targetPixel) =>
{
// reads the pixel color
Color color = GetColorFromPixel(sourcePixel);
// converts alpha to solid color
color = QuantizationHelper.ConvertAlpha(color);
// quantizes the pixel
SetColorToPixel(targetPixel, color, quantizer);
// marks pixel as processed by default
Boolean result = true;
// preforms inplace dithering (optional)
if (ditherer != null && ditherer.IsInplace)
{
result = ditherer.ProcessPixel(sourcePixel, targetPixel);
}
// returns the result
return(result);
};
// step 5 - generates the target image
IList <Point> path = quantizer.GetPointPath(Width, Height);
TransformPerPixel(target, path, quantize, parallelTaskCount);
// step 6 - preforms non-inplace dithering (optional)
if (ditherer != null && !ditherer.IsInplace)
{
Dither(target, ditherer, quantizer, colorCount, 1);
}
// step 7 - finishes the dithering (optional)
if (ditherer != null)
{
ditherer.Finish();
}
// step 8 - clean-up
quantizer.Finish();
}
