private static ColorData BuildHistogram(Bitmap sourceImage, int alphaThreshold, int alphaFader)
{
int bitmapWidth = sourceImage.Width;
int bitmapHeight = sourceImage.Height;
BitmapData data = sourceImage.LockBits(
Rectangle.FromLTRB(0, 0, bitmapWidth, bitmapHeight),
ImageLockMode.ReadOnly,
sourceImage.PixelFormat);
ColorData colorData = new ColorData(MaxSideIndex, bitmapWidth, bitmapHeight);
try
{
var bitDepth = Image.GetPixelFormatSize(sourceImage.PixelFormat);
if (bitDepth != 32)
{
throw new QuantizationException(string.Format("Thie image you are attempting to quantize does not contain a 32 bit ARGB palette. This image has a bit depth of {0} with {1} colors.", bitDepth, sourceImage.Palette.Entries.Length));
}
var byteLength = data.Stride < 0 ? -data.Stride : data.Stride;
var byteCount = Math.Max(1, bitDepth >> 3);
var offset = 0;
var buffer = new Byte[byteLength * sourceImage.Height];
var value = new Byte[byteCount];
Marshal.Copy(data.Scan0, buffer, 0, buffer.Length);
for (int y = 0; y < bitmapHeight; y++)
{
var index = 0;
for (int x = 0; x < bitmapWidth; x++)
{
var indexOffset = index >> 3;
for (var valueIndex = 0; valueIndex < byteCount; valueIndex++)
{
value[valueIndex] = buffer[offset + valueIndex + indexOffset];
}
var indexAlpha = (byte)((value[Alpha] >> 3) + 1);
var indexRed = (byte)((value[Red] >> 3) + 1);
var indexGreen = (byte)((value[Green] >> 3) + 1);
var indexBlue = (byte)((value[Blue] >> 3) + 1);
if (value[Alpha] > alphaThreshold)
{
if (value[Alpha] < 255)
{
var alpha = value[Alpha] + (value[Alpha] % alphaFader);
value[Alpha] = (byte)(alpha > 255 ? 255 : alpha);
indexAlpha = (byte)((value[Alpha] >> 3) + 1);
}
colorData.Weights[indexAlpha, indexRed, indexGreen, indexBlue]++;
colorData.MomentsRed[indexAlpha, indexRed, indexGreen, indexBlue] += value[Red];
colorData.MomentsGreen[indexAlpha, indexRed, indexGreen, indexBlue] += value[Green];
colorData.MomentsBlue[indexAlpha, indexRed, indexGreen, indexBlue] += value[Blue];
colorData.MomentsAlpha[indexAlpha, indexRed, indexGreen, indexBlue] += value[Alpha];
colorData.Moments[indexAlpha, indexRed, indexGreen, indexBlue] += (value[Alpha] * value[Alpha]) +
(value[Red] * value[Red]) +
(value[Green] * value[Green]) +
(value[Blue] * value[Blue]);
}
colorData.AddPixel(
new Pixel(value[Alpha], value[Red], value[Green], value[Blue]),
BitConverter.ToInt32(new[] { indexAlpha, indexRed, indexGreen, indexBlue }, 0));
index += bitDepth;
}
offset += byteLength;
}
}
finally
{
sourceImage.UnlockBits(data);
}
return(colorData);
}
private bool Cut(ColorData data, ref Box first, ref Box second)
{
int direction;
var wholeAlpha = Volume(first, data.MomentsAlpha);
var wholeRed = Volume(first, data.MomentsRed);
var wholeGreen = Volume(first, data.MomentsGreen);
var wholeBlue = Volume(first, data.MomentsBlue);
var wholeWeight = Volume(first, data.Weights);
var maxAlpha = Maximize(data, first, Alpha, (byte)(first.AlphaMinimum + 1), first.AlphaMaximum, wholeAlpha, wholeRed, wholeGreen, wholeBlue, wholeWeight);
var maxRed = Maximize(data, first, Red, (byte)(first.RedMinimum + 1), first.RedMaximum, wholeAlpha, wholeRed, wholeGreen, wholeBlue, wholeWeight);
var maxGreen = Maximize(data, first, Green, (byte)(first.GreenMinimum + 1), first.GreenMaximum, wholeAlpha, wholeRed, wholeGreen, wholeBlue, wholeWeight);
var maxBlue = Maximize(data, first, Blue, (byte)(first.BlueMinimum + 1), first.BlueMaximum, wholeAlpha, wholeRed, wholeGreen, wholeBlue, wholeWeight);
if ((maxAlpha.Value >= maxRed.Value) && (maxAlpha.Value >= maxGreen.Value) && (maxAlpha.Value >= maxBlue.Value))
{
direction = Alpha;
if (maxAlpha.Position == null)
{
return(false);
}
}
else if ((maxRed.Value >= maxAlpha.Value) && (maxRed.Value >= maxGreen.Value) && (maxRed.Value >= maxBlue.Value))
{
direction = Red;
}
else
{
if ((maxGreen.Value >= maxAlpha.Value) && (maxGreen.Value >= maxRed.Value) && (maxGreen.Value >= maxBlue.Value))
{
direction = Green;
}
else
{
direction = Blue;
}
}
second.AlphaMaximum = first.AlphaMaximum;
second.RedMaximum = first.RedMaximum;
second.GreenMaximum = first.GreenMaximum;
second.BlueMaximum = first.BlueMaximum;
switch (direction)
{
case Alpha:
second.AlphaMinimum = first.AlphaMaximum = (byte)maxAlpha.Position;
second.RedMinimum = first.RedMinimum;
second.GreenMinimum = first.GreenMinimum;
second.BlueMinimum = first.BlueMinimum;
break;
case Red:
second.RedMinimum = first.RedMaximum = (byte)maxRed.Position;
second.AlphaMinimum = first.AlphaMinimum;
second.GreenMinimum = first.GreenMinimum;
second.BlueMinimum = first.BlueMinimum;
break;
case Green:
second.GreenMinimum = first.GreenMaximum = (byte)maxGreen.Position;
second.AlphaMinimum = first.AlphaMinimum;
second.RedMinimum = first.RedMinimum;
second.BlueMinimum = first.BlueMinimum;
break;
case Blue:
second.BlueMinimum = first.BlueMaximum = (byte)maxBlue.Position;
second.AlphaMinimum = first.AlphaMinimum;
second.RedMinimum = first.RedMinimum;
second.GreenMinimum = first.GreenMinimum;
break;
}
first.Size = (first.AlphaMaximum - first.AlphaMinimum) * (first.RedMaximum - first.RedMinimum) * (first.GreenMaximum - first.GreenMinimum) * (first.BlueMaximum - first.BlueMinimum);
second.Size = (second.AlphaMaximum - second.AlphaMinimum) * (second.RedMaximum - second.RedMinimum) * (second.GreenMaximum - second.GreenMinimum) * (second.BlueMaximum - second.BlueMinimum);
return(true);
}
protected abstract QuantizedPalette GetQuantizedPalette(int colorCount, ColorData data, IEnumerable <Box> cubes, int alphaThreshold);
private static ColorData CalculateMoments(ColorData data)
{
for (var alphaIndex = 1; alphaIndex <= MaxSideIndex; ++alphaIndex)
{
var xarea = new long[SideSize, SideSize, SideSize];
var xareaAlpha = new long[SideSize, SideSize, SideSize];
var xareaRed = new long[SideSize, SideSize, SideSize];
var xareaGreen = new long[SideSize, SideSize, SideSize];
var xareaBlue = new long[SideSize, SideSize, SideSize];
var xarea2 = new float[SideSize, SideSize, SideSize];
for (var redIndex = 1; redIndex <= MaxSideIndex; ++redIndex)
{
var area = new long[SideSize];
var areaAlpha = new long[SideSize];
var areaRed = new long[SideSize];
var areaGreen = new long[SideSize];
var areaBlue = new long[SideSize];
var area2 = new float[SideSize];
for (var greenIndex = 1; greenIndex <= MaxSideIndex; ++greenIndex)
{
long line = 0;
long lineAlpha = 0;
long lineRed = 0;
long lineGreen = 0;
long lineBlue = 0;
var line2 = 0.0f;
for (var blueIndex = 1; blueIndex <= MaxSideIndex; ++blueIndex)
{
line += data.Weights[alphaIndex, redIndex, greenIndex, blueIndex];
lineAlpha += data.MomentsAlpha[alphaIndex, redIndex, greenIndex, blueIndex];
lineRed += data.MomentsRed[alphaIndex, redIndex, greenIndex, blueIndex];
lineGreen += data.MomentsGreen[alphaIndex, redIndex, greenIndex, blueIndex];
lineBlue += data.MomentsBlue[alphaIndex, redIndex, greenIndex, blueIndex];
line2 += data.Moments[alphaIndex, redIndex, greenIndex, blueIndex];
area[blueIndex] += line;
areaAlpha[blueIndex] += lineAlpha;
areaRed[blueIndex] += lineRed;
areaGreen[blueIndex] += lineGreen;
areaBlue[blueIndex] += lineBlue;
area2[blueIndex] += line2;
xarea[redIndex, greenIndex, blueIndex] = xarea[redIndex - 1, greenIndex, blueIndex] + area[blueIndex];
xareaAlpha[redIndex, greenIndex, blueIndex] = xareaAlpha[redIndex - 1, greenIndex, blueIndex] + areaAlpha[blueIndex];
xareaRed[redIndex, greenIndex, blueIndex] = xareaRed[redIndex - 1, greenIndex, blueIndex] + areaRed[blueIndex];
xareaGreen[redIndex, greenIndex, blueIndex] = xareaGreen[redIndex - 1, greenIndex, blueIndex] + areaGreen[blueIndex];
xareaBlue[redIndex, greenIndex, blueIndex] = xareaBlue[redIndex - 1, greenIndex, blueIndex] + areaBlue[blueIndex];
xarea2[redIndex, greenIndex, blueIndex] = xarea2[redIndex - 1, greenIndex, blueIndex] + area2[blueIndex];
data.Weights[alphaIndex, redIndex, greenIndex, blueIndex] = data.Weights[alphaIndex - 1, redIndex, greenIndex, blueIndex] + xarea[redIndex, greenIndex, blueIndex];
data.MomentsAlpha[alphaIndex, redIndex, greenIndex, blueIndex] = data.MomentsAlpha[alphaIndex - 1, redIndex, greenIndex, blueIndex] + xareaAlpha[redIndex, greenIndex, blueIndex];
data.MomentsRed[alphaIndex, redIndex, greenIndex, blueIndex] = data.MomentsRed[alphaIndex - 1, redIndex, greenIndex, blueIndex] + xareaRed[redIndex, greenIndex, blueIndex];
data.MomentsGreen[alphaIndex, redIndex, greenIndex, blueIndex] = data.MomentsGreen[alphaIndex - 1, redIndex, greenIndex, blueIndex] + xareaGreen[redIndex, greenIndex, blueIndex];
data.MomentsBlue[alphaIndex, redIndex, greenIndex, blueIndex] = data.MomentsBlue[alphaIndex - 1, redIndex, greenIndex, blueIndex] + xareaBlue[redIndex, greenIndex, blueIndex];
data.Moments[alphaIndex, redIndex, greenIndex, blueIndex] = data.Moments[alphaIndex - 1, redIndex, greenIndex, blueIndex] + xarea2[redIndex, greenIndex, blueIndex];
}
}
}
}
return(data);
}