public ColorQuantizer(int NumColors)
{
m_pCubeInfo = null;
m_pQuantizeInfo = new QuantizeInfo();
m_Depth = 8;
m_Colors = NumColors;
m_pQuantizeInfo.Clear();
m_pQuantizeInfo.number_colors = NumColors;
m_pQuantizeInfo.dither = 0;
// Depth of color tree is: Log4(colormap size)+2.
int colors = NumColors;
for (m_Depth = 1; colors != 0; m_Depth++)
{
colors >>= 2;
}
if (m_pQuantizeInfo.dither > 0)
{
m_Depth--;
}
m_Depth += 2;
m_pCubeInfo = GetCubeInfo(m_pQuantizeInfo, m_Depth);
}
CubeInfo GetCubeInfo(QuantizeInfo quantize_info, int depth)
{
CubeInfo cube_info;
double sum,
weight;
// Initialize tree to describe color cube_info.
cube_info = new CubeInfo();
if (depth > MaxTreeDepth)
{
depth = MaxTreeDepth;
}
if (depth < 2)
{
depth = 2;
}
cube_info.depth = depth;
// Initialize root node.
cube_info.root = GetNodeInfo(cube_info, 0, 0, null);
if (cube_info.root == null)
{
return(null);
}
cube_info.root.parent = cube_info.root;
cube_info.quantize_info = quantize_info;
if (cube_info.quantize_info.dither == 0)
{
return(cube_info);
}
// Initialize dither resources.
cube_info.cache = new List <long>((1 << 18));
// Initialize color cache.
for (int i = 0; i < (1 << 18); i++)
{
cube_info.cache[i] = (-1);
}
// Distribute weights along a curve of exponential decay.
weight = 1.0;
for (int i = 0; i < ExceptionQueueLength; i++)
{
cube_info.weights[ExceptionQueueLength - i - 1] = 1.0 / weight;
weight *= Math.Exp(Math.Log((double)(MaxRGB() + 1)) / (ExceptionQueueLength - 1.0));
}
// Normalize the weighting factors.
weight = 0.0;
for (int i = 0; i < ExceptionQueueLength; i++)
{
weight += cube_info.weights[i];
}
sum = 0.0;
for (int i = 0; i < ExceptionQueueLength; i++)
{
cube_info.weights[i] /= weight;
sum += cube_info.weights[i];
}
cube_info.weights[0] += 1.0 - sum;
return(cube_info);
}
