public static unsafe SKPixmap WaveletUpscale(this SKImage image, Wavelet wavelet)
{
int width = image.Width;
int height = image.Height;
int upscaledWidth = width * 2;
int upscaledHeight = height * 2;
float[,] y = new float[upscaledWidth, upscaledWidth];
float[,] cb = new float[upscaledWidth, upscaledWidth];
float[,] cr = new float[upscaledWidth, upscaledWidth];
float[,] a = new float[upscaledWidth, upscaledWidth];
image.ToYCbCrAArrays(y, cb, cr, a);
WaveletTransform2D wavelet2D;
WaveletTransform2D upscaledWavelet2D;
switch (wavelet)
{
case Wavelet.Haar:
wavelet2D = new HaarWavelet2D(width, height);
upscaledWavelet2D = new HaarWavelet2D(upscaledWidth, upscaledHeight);
break;
case Wavelet.Biorthogonal53:
default:
wavelet2D = new Biorthogonal53Wavelet2D(width, height);
upscaledWavelet2D = new Biorthogonal53Wavelet2D(upscaledWidth, upscaledHeight);
break;
}
wavelet2D.Transform2D(y);
wavelet2D.Transform2D(cb);
wavelet2D.Transform2D(cr);
wavelet2D.Transform2D(a);
upscaledWavelet2D.ReverseTransform2D(y);
upscaledWavelet2D.ReverseTransform2D(cb);
upscaledWavelet2D.ReverseTransform2D(cr);
upscaledWavelet2D.ReverseTransform2D(a);
for (int row = 0; row < upscaledHeight; row++)
{
for (int col = 0; col < upscaledWidth; col++)
{
y[col, row] *= 4.0f;
cb[col, row] *= 4.0f;
cr[col, row] *= 4.0f;
a[col, row] *= 4.0f;
}
}
SKImageInfo info = new SKImageInfo(upscaledWidth, upscaledHeight, SKColorType.Rgba8888);
SKImage output = SKImage.Create(info);
SKPixmap pixmap = output.ToRGBAPixmap(y, cb, cr, a);
return(pixmap);
}