// Maps image colors to the color map
protected void AnalyzePixels()
{
int len = m_Pixels.Length;
int nPix = len / 3;
m_IndexedPixels = new byte[nPix];
// Analyze image colors and create color map (original, expensive, Moments Recorder behaviour)
if (m_FramesPerColorSample == 0)
{
nq = new NeuQuant(m_Pixels, len, (int)m_SampleInterval);
m_ColorTab = nq.Process(); // Create reduced palette
}
// Map image pixels to new palette
int k = 0;
for (int i = 0; i < nPix; i++)
{
int index = nq.Map(m_Pixels[k++] & 0xff, m_Pixels[k++] & 0xff, m_Pixels[k++] & 0xff);
m_UsedEntry[index] = true;
m_IndexedPixels[i] = (byte)index;
}
m_Pixels = null;
m_ColorDepth = 8;
m_PaletteSize = 7;
}
/// <summary>
/// Builds a colour map out of the combined colours from several frames.
/// </summary>
/// <param name="frames">List of frames to sample colour palette from</param>
public void BuildPalette(ref FixedSizedQueue <GifFrame> frames)
{
// Do not build the color palette here if user wants separate palettes created per frame
if (m_FramesPerColorSample == 0)
{
return;
}
GifFrame frame = frames.ElementAt(0);
// Initialize a large image
Byte[] combinedPixels = new Byte[3 * frame.Width * frame.Height * (1 + frames.Count() / m_FramesPerColorSample)];
int count = 0;
// Stich the large image together out of pixels from several frames
for (int i = 0; i < frames.Count(); i += m_FramesPerColorSample)
{
frame = frames.ElementAt(0);
Color32[] p = frame.Data;
// Texture data is layered down-top, so flip it
for (int th = frame.Height - 1; th >= 0; th--)
{
for (int tw = 0; tw < frame.Width; tw++)
{
Color32 color = p[th * frame.Width + tw];
combinedPixels[count] = color.r; count++;
combinedPixels[count] = color.g; count++;
combinedPixels[count] = color.b; count++;
}
}
}
// Run the quantizer over our stitched together image and create reduced palette
nq = new NeuQuant(combinedPixels, combinedPixels.Length, (int)m_SampleInterval);
m_ColorTab = nq.Process();
}
