public static byte[] FromBitmap(Bitmap bmp, ConvertionMethod method, DitheringMethod dither, bool serpentine, int grayScaleDepth)
{
if (!(new[] { 2, 4, 8, 16, 32, 64, 128, 256 }).Contains(grayScaleDepth))
{
throw new Exception("GrayScaleDepth must be a power of 2 between 1 and 254");
}
byte[] output = new byte[0];
output = ConvertToGrayscale(bmp, method, grayScaleDepth);
output = Dither(output, grayScaleDepth, bmp.Width, bmp.Height, dither, serpentine);
return(output);
}
private static DitheringBase <byte> GetDitherer(DitheringMethod method, DitheringBase <byte> .ColorFunction colorfunc) =>
method switch
{
public static (bool valid, string possibleError, DitheringMethod dithering, ColorReductionMethod colorReduction, OutputFormat outputFormat, string inputFile, string outputFile) ParseParameters(string[] args)
{
if (!File.Exists(args[0]))
{
return(false, "Cannot find input file!", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
string input = args[0];
int ditheringMethodValueIndex = FindParameterIndex(args, "-m");
if (ditheringMethodValueIndex < 0)
{
return(false, "Missing parameter -m !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
ditheringMethodValueIndex++;
if (ditheringMethodValueIndex == args.Length)
{
return(false, "Missing parameter -m value !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
int colorReductionMethodValueIndex = FindParameterIndex(args, "-c");
if (colorReductionMethodValueIndex < 0)
{
return(false, "Missing parameter -c !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
colorReductionMethodValueIndex++;
if (colorReductionMethodValueIndex == args.Length)
{
return(false, "Missing parameter -c value !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
int formatValueIndex = FindParameterIndex(args, "-f");
if (formatValueIndex < 0)
{
return(false, "Missing parameter -f !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
formatValueIndex++;
if (formatValueIndex == args.Length)
{
return(false, "Missing parameter -f value !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
int outputFileValueIndex = FindParameterIndex(args, "-o");
if (outputFileValueIndex < 0)
{
return(false, "Missing parameter -o !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
outputFileValueIndex++;
if (outputFileValueIndex == args.Length)
{
return(false, "Missing parameter -o value !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
DitheringMethod ditheringMethod = DitheringMethod.None;
string ditheringMethodString = args[ditheringMethodValueIndex];
try
{
ditheringMethod = (DitheringMethod)Enum.Parse(typeof(DitheringMethod), ditheringMethodString, ignoreCase: true);
if (!Enum.IsDefined(typeof(DitheringMethod), ditheringMethod))
{
return(false, $"Cannot parse dithering method from {ditheringMethodString} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
}
catch
{
return(false, $"Cannot parse dithering method from {ditheringMethodString} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
if (ditheringMethod == DitheringMethod.None)
{
return(false, $"Cannot use None as dithering!", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
ColorReductionMethod colorReductionMethod = ColorReductionMethod.None;
string colorReductionMethodString = args[colorReductionMethodValueIndex];
try
{
colorReductionMethod = (ColorReductionMethod)Enum.Parse(typeof(ColorReductionMethod), colorReductionMethodString, ignoreCase: true);
if (!Enum.IsDefined(typeof(ColorReductionMethod), colorReductionMethod))
{
return(false, $"Cannot parse color reduction method from {colorReductionMethodString} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
}
catch
{
return(false, $"Cannot parse color reduction method from {colorReductionMethodString} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
if (colorReductionMethod == ColorReductionMethod.None)
{
return(false, $"Cannot use None as color reduce method!", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
OutputFormat outputFormat = OutputFormat.None;
string outputFormatString = args[formatValueIndex];
try
{
outputFormat = (OutputFormat)Enum.Parse(typeof(OutputFormat), outputFormatString, ignoreCase: true);
if (!Enum.IsDefined(typeof(OutputFormat), outputFormat))
{
return(false, $"Cannot parse output format from {outputFormatString} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
}
catch
{
return(false, $"Cannot parse output format from {outputFormatString} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
string outputFileName = args[outputFileValueIndex];
if (File.Exists(outputFileName))
{
return(false, $"Cannot overwrite existing file {outputFileName} !", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
if (outputFormat == OutputFormat.HTMLBasic)
{
if (!outputFileName.EndsWith(".html") && !outputFileName.EndsWith(".htm"))
{
return(false, $"HTML output must use .html or .htm file extension!", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
}
else if (outputFormat == OutputFormat.SingleImage)
{
if (!outputFileName.EndsWith(".png"))
{
return(false, $"Image output must use .png file extension!", DitheringMethod.None, ColorReductionMethod.None, OutputFormat.None, "", "");
}
}
return(true, "", ditheringMethod, colorReductionMethod, outputFormat, input, outputFileName);
}
public static byte[] Dither(byte[] data, int grayScaleDepth, int width, int height, DitheringMethod method, bool serpentine = true, double bleedRatio = 1)
{
int[] integerData = data.Select(item => (int)item).ToArray();
List <byte> realGrayPoints = new List <byte>();
Dictionary <byte, byte> realGrayToIdx = new Dictionary <byte, byte>();
double tempGrayPoint = 0;
byte grayPointIterator = 0;
while (Math.Round(tempGrayPoint) <= 255)
{
realGrayPoints.Add((byte)tempGrayPoint);
realGrayToIdx.Add((byte)tempGrayPoint, grayPointIterator);
grayPointIterator++;
tempGrayPoint += 255.0 / (grayScaleDepth - 1);
}
byte[] scaleValueMatrix = new byte[256];
int[] scaleErrorMatrix = new int[256];
for (int i = 0; i <= 255; i++)
{
var i1 = i;
var grayErrors = realGrayPoints.Select(item => new { error = i1 - item, gray = item }).OrderBy(item => Math.Abs(item.error));
scaleValueMatrix[i] = grayErrors.First().gray;
scaleErrorMatrix[i] = grayErrors.First().error;
}
byte ditherDivider = 1;
byte?[,] ditherMatrix = new byte?[1, 1];
byte?[,] reverseDitherMatrix = new byte?[1, 1];
byte xOrigin = 0;
byte reverseXOrigin = 0;
byte yOrigin = 0;
switch (method)
{
case DitheringMethod.None:
ditherDivider = 1;
ditherMatrix = new byte?[1, 1]
{
{ null }
};
reverseDitherMatrix = new byte?[1, 1]
{
{ null }
};
xOrigin = 0;
reverseXOrigin = 0;
yOrigin = 0;
break;
case DitheringMethod.Simple:
ditherDivider = 1;
ditherMatrix = new byte?[1, 2]
{
{ null, 1 }
};
reverseDitherMatrix = new byte?[1, 2]
{
{ 1, null }
};
xOrigin = 0;
reverseXOrigin = 1;
yOrigin = 0;
break;
case DitheringMethod.FloydSteinberg:
ditherDivider = 16;
ditherMatrix = new byte?[2, 3]
{
{ null, null, 7 },
{ 3, 5, 1 }
};
reverseDitherMatrix = new byte?[2, 3]
{
{ 7, null, null },
{ 1, 5, 3 }
};
xOrigin = 1;
reverseXOrigin = 1;
yOrigin = 0;
break;
case DitheringMethod.JarvisJudiceNinke:
ditherDivider = 48;
ditherMatrix = new byte?[3, 5]
{
{ null, null, null, 7, 5 },
{ 3, 5, 7, 5, 3 },
{ 1, 3, 5, 3, 1 }
};
reverseDitherMatrix = new byte?[3, 5]
{
{ 5, 7, null, null, null },
{ 3, 5, 7, 5, 3 },
{ 1, 3, 5, 3, 1 }
};
xOrigin = 2;
reverseXOrigin = 2;
yOrigin = 0;
break;
case DitheringMethod.Stucki:
ditherDivider = 42;
ditherMatrix = new byte?[3, 5]
{
{ null, null, null, 8, 4 },
{ 2, 4, 8, 4, 2 },
{ 1, 2, 4, 2, 1 }
};
reverseDitherMatrix = new byte?[3, 5]
{
{ 4, 8, null, null, null },
{ 2, 4, 8, 4, 2 },
{ 1, 2, 4, 2, 1 }
};
xOrigin = 2;
reverseXOrigin = 2;
yOrigin = 0;
break;
case DitheringMethod.Atkinson:
ditherDivider = 8;
ditherMatrix = new byte?[3, 4]
{
{ null, null, 1, 1 },
{ 1, 1, 1, null },
{ null, 1, null, null }
};
reverseDitherMatrix = new byte?[3, 4]
{
{ 1, 1, null, null },
{ null, 1, 1, 1 },
{ null, null, 1, null }
};
xOrigin = 1;
reverseXOrigin = 2;
yOrigin = 0;
break;
case DitheringMethod.Burkes:
ditherDivider = 32;
ditherMatrix = new byte?[2, 5]
{
{ null, null, null, 8, 4 },
{ 2, 4, 8, 4, 2 }
};
reverseDitherMatrix = new byte?[2, 5]
{
{ 4, 8, null, null, null },
{ 2, 4, 8, 4, 2 }
};
xOrigin = 2;
reverseXOrigin = 2;
yOrigin = 0;
break;
case DitheringMethod.Sierra:
ditherDivider = 32;
ditherMatrix = new byte?[3, 5]
{
{ null, null, null, 5, 3 },
{ 2, 4, 5, 1, 2 },
{ null, 2, 3, 2, null }
};
reverseDitherMatrix = new byte?[3, 5]
{
{ 3, 5, null, null, null },
{ 2, 1, 5, 4, 2 },
{ null, 2, 3, 2, null }
};
xOrigin = 2;
reverseXOrigin = 2;
yOrigin = 0;
break;
case DitheringMethod.TwoRowSierra:
ditherDivider = 16;
ditherMatrix = new byte?[2, 5]
{
{ null, null, null, 4, 3 },
{ 1, 2, 3, 2, 1 }
};
reverseDitherMatrix = new byte?[2, 5]
{
{ 3, 4, null, null, null },
{ 1, 2, 3, 2, 1 }
};
xOrigin = 2;
reverseXOrigin = 2;
yOrigin = 0;
break;
case DitheringMethod.SierraLite:
ditherDivider = 4;
ditherMatrix = new byte?[2, 3]
{
{ null, null, 2 },
{ 1, 1, null }
};
reverseDitherMatrix = new byte?[2, 3]
{
{ 2, null, null },
{ null, 1, 1 }
};
xOrigin = 1;
reverseXOrigin = 1;
yOrigin = 0;
break;
default:
throw new ArgumentOutOfRangeException(nameof(method), method, null);
}
for (int y = 0; y < height; y++)
{
if (!(serpentine && y % 2 == 0))
{
for (int x = 0; x < width; x++)
{
int pixelVal = integerData[y * width + x];
if (pixelVal > 255)
{
pixelVal = 255;
}
else if (pixelVal < 0)
{
pixelVal = 0;
}
integerData[y * width + x] = realGrayToIdx[scaleValueMatrix[pixelVal]];
double error = scaleErrorMatrix[pixelVal];
error = Math.Round(error * bleedRatio / ditherDivider);
for (int ditherY = 0; ditherY < ditherMatrix.GetLength(0); ditherY++)
{
int subY = y - yOrigin + ditherY;
if (subY >= height)
{
break;
}
else if (subY < 0)
{
continue;
}
for (int ditherX = 0; ditherX < ditherMatrix.GetLength(1); ditherX++)
{
int subX = x - xOrigin + ditherX;
if (subX >= width)
{
break;
}
else if (subX < 0)
{
continue;
}
byte?dietherFract = ditherMatrix[ditherY, ditherX];
if (dietherFract == null)
{
continue;
}
double val = integerData[subY * width + subX];
val += error * dietherFract ?? 1;
integerData[subY * width + subX] = (int)Math.Round(val);
}
}
}
}
else
{
for (int x = width - 1; x >= 0; x--)
{
int pixelVal = integerData[y * width + x];
if (pixelVal > 255)
{
pixelVal = 255;
}
else if (pixelVal < 0)
{
pixelVal = 0;
}
integerData[y * width + x] = realGrayToIdx[scaleValueMatrix[pixelVal]];
double error = scaleErrorMatrix[pixelVal];
error = Math.Round(error * bleedRatio / ditherDivider);
for (int ditherY = 0; ditherY < reverseDitherMatrix.GetLength(0); ditherY++)
{
int subY = y - yOrigin + ditherY;
if (subY >= height)
{
break;
}
else if (subY < 0)
{
continue;
}
for (int ditherX = 0; ditherX < reverseDitherMatrix.GetLength(1); ditherX++)
{
int subX = x - reverseXOrigin + ditherX;
if (subX >= width)
{
break;
}
else if (subX < 0)
{
continue;
}
byte?dietherFract = reverseDitherMatrix[ditherY, ditherX];
if (dietherFract == null)
{
continue;
}
double val = integerData[subY * width + subX];
val += error * dietherFract ?? 1;
integerData[subY * width + subX] = (int)Math.Round(val);
}
}
}
}
}
return(integerData.Select(item => (byte)item).ToArray());
}
