public static Bitmap Quantize(Bitmap bitmap, int colourCount)
{
var quantizer = new PaletteQuantizer();
for (int x = 0; x < bitmap.Width; x++)
{
for (int y = 0; y < bitmap.Height; y++)
{
var colour = bitmap.GetPixel(x, y);
quantizer.AddColour(colour);
}
}
quantizer.Quantize(colourCount);
var ret = new Bitmap(bitmap.Width, bitmap.Height);
for (int x = 0; x < bitmap.Width; x++)
{
for (int y = 0; y < bitmap.Height; y++)
{
var colour = quantizer.GetQuantizedColour(bitmap.GetPixel(x, y));
ret.SetPixel(x, y, colour);
}
}
return(ret);
}
/// <summary>
/// Generates an indexed 256-color palette from the specified image and overwrites the current palette with it.
/// Ordinarily, this would be the original mipmap.
/// </summary>
/// <param name="inImage">Image.</param>
private void GeneratePalette(Image inImage)
{
// TODO: Replace with an algorithm that produces a better result. For now, it works.
PaletteQuantizer quantizer = new PaletteQuantizer(new ArrayList());
using (Bitmap quantizedMap = quantizer.Quantize(inImage))
{
this.Palette.Clear();
this.Palette.AddRange(quantizedMap.Palette.Entries);
}
}
public void PaletteQuantizerYieldsCorrectTransparentPixel <TPixel>(TestImageProvider <TPixel> provider, bool dither)
where TPixel : struct, IPixel <TPixel>
{
using (Image <TPixel> image = provider.GetImage())
{
Assert.True(image[0, 0].Equals(default(TPixel)));
IQuantizer <TPixel> quantizer = new PaletteQuantizer <TPixel> {
Dither = dither
};
foreach (ImageFrame <TPixel> frame in image.Frames)
{
QuantizedImage <TPixel> quantized = quantizer.Quantize(frame, 256);
int index = this.GetTransparentIndex(quantized);
Assert.Equal(index, quantized.Pixels[0]);
}
}
}
