public ImagesCorrelationStats(ITextureCache cache)
{
this.Cache = cache;
Image1 = new ImageVarianceStats(cache);
Image2 = new ImageVarianceStats(cache);
Correlation = cache.GetTexture();
}
private void RenderImageVariance(ITexture src, ImageVarianceStats dst, LayerMipmapSlice lm)
{
// luma values
lumaTransformShader.Run(src, dst.Luma, lm, models.SharedModel.Upload);
// expected value
gaussShader.Run(dst.Luma, dst.Expected, lm, models.SharedModel.Upload, dst.Cache);
// calculate luma squared
var lumaSq = dst.Cache.GetTexture();
multiplyShader.Run(new [] { dst.Luma, dst.Luma }, lumaSq, lm, models.SharedModel.Upload);
// blur luma squared
var lumaBlur = dst.Cache.GetTexture();
gaussShader.Run(lumaSq, lumaBlur, lm, models.SharedModel.Upload, dst.Cache);
// calc variance with: blurred(luma^2) - mu^2
subtractProductShader.Run(new [] { lumaBlur, dst.Expected, dst.Expected }, dst.Variance, lm, models.SharedModel.Upload);
dst.Cache.StoreTexture(lumaSq);
dst.Cache.StoreTexture(lumaBlur);
}