private static Difference[,] CalculateDistances(Color[][] palettes)
{
// Combination of each palette with each palette except with itself (diagonal)
Difference[,] distances = new Difference[palettes.Length, palettes.Length];
// Convert palettes to labcolor space to compute difference
LabColor[][] labPalettes = new LabColor[palettes.Length][];
for (int i = 0; i < palettes.Length; i++)
{
labPalettes[i] = ColorConversion.ToLabPalette <Color>(palettes[i]);
}
// Compute every possible difference
for (int i = 0; i < palettes.Length; i++)
{
for (int j = 0; j < palettes.Length; j++)
{
if (i == j)
{
continue;
}
distances[i, j] = new Difference();
distances[i, j].SrcPalette = i;
distances[i, j].DstPalette = j;
distances[i, j].Distance = PaletteDistance.CalculateDistance(
labPalettes[i], labPalettes[j]);
}
}
return(distances);
}
protected override void PreQuantization(Emgu.CV.Image <Color, byte> image)
{
this.image = image;
// If only there is one, do nothing
if (this.palettes.Length == 1)
{
base.PreQuantization(image);
return;
}
// Extract a palette from the image removing transparent colors (not approximated)
this.compareQuantization.TileSize = this.TileSize;
this.compareQuantization.Quantizate(image);
Color[] comparePalette = this.compareQuantization.Palette.
Where(c => c.Alpha == 255).ToArray();
LabColor[] compareLabPalette = ColorConversion.ToLabPalette <Color>(comparePalette);
// Compare all possible palettes to get the similar one
double minDistance = Double.MaxValue;
for (int i = 0; i < palettes.Length && minDistance > 0; i++)
{
double distance = PaletteDistance.CalculateDistance(
compareLabPalette, this.labPalettes[i]);
if (distance < minDistance)
{
this.SelectedPalette = i;
minDistance = distance;
}
}
// Set the palette...
this.Palette = this.palettes[this.SelectedPalette];
// ... and run the FixedPaletteQuantization
base.PreQuantization(image);
}