public ImageDecoderIndexed(byte[] pixelData, int width, int height, IndexCodec codec, SKColor[] palette = null, ImageFilter imageFilter = null, PaletteFilter paletteFilter = null)
{
this.pixelData = pixelData;
if (imageFilter != null)
{
this.pixelData = imageFilter.Defilter(pixelData);
}
this.width = width;
this.height = height;
this.indexCodec = codec;
grayScale = new SKColor[1 << codec.BitDepth];
for (int i = 0; i < grayScale.Length; i++)
{
grayScale[i] = new SKColor((byte)(i * (256 / grayScale.Length)), (byte)(i * (256 / grayScale.Length)), (byte)(i * (256 / grayScale.Length)));
}
if (paletteFilter != null && palette != null)
{
Palette = paletteFilter.Defilter(palette);
}
else if (palette == null)
{
palette = (SKColor[])grayScale.Clone();
Palette = palette;
}
else
{
Palette = (SKColor[])palette.Clone();
}
}
public override SKColor[] DecodeColors(byte[] colors, int start, int length)
{
ImageFilter filter = GetImageFilter();
BinaryReader reader = null;
if (filter != null)
{
byte[] data = filter.Defilter(colors, start, length);
reader = new BinaryReader(new MemoryStream(data));
}
else
{
reader = new BinaryReader(new MemoryStream(colors, start, length));
}
SKColor[] decoded = new SKColor[FullWidth * FullHeight];
SKColor[] tile = new SKColor[4 * 4];
for (int y = 0; y < FullHeight; y += 4)
{
for (int x = 0; x < FullWidth; x += 4)
{
DecodeDXT1Block(reader, tile);
for (int line = 0; line < 4; line++)
{
int destIndex = FullWidth * (y + line) +
(ByteOrder == ByteOrder.BigEndian ? x : FullWidth - (x + 4));
Array.Copy(tile, line * 4, decoded, destIndex, 4);
}
}
}
reader.Close();
if (FullWidth == width && FullHeight == height)
{
return(decoded);
}
SKColor[] decodedRealSize = new SKColor[width * height];
int k = 0;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
decodedRealSize[k++] = decoded[y * FullWidth + x];
}
}
return(decodedRealSize);
}
public ImageDecoderDirectColor(byte[] pixelData, int width, int height, ColorCodec decoder, ImageFilter imageFilter = null)
{
this.pixelData = pixelData;
if (imageFilter != null)
{
this.pixelData = imageFilter.Defilter(pixelData);
}
this.width = width;
this.height = height;
this.decoder = decoder;
}
