diff options
Diffstat (limited to 'intern/cycles/kernel/filter/filter_prefilter.h')
| -rw-r--r-- | intern/cycles/kernel/filter/filter_prefilter.h | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/intern/cycles/kernel/filter/filter_prefilter.h b/intern/cycles/kernel/filter/filter_prefilter.h index 8211311313d..b48a3f3f68b 100644 --- a/intern/cycles/kernel/filter/filter_prefilter.h +++ b/intern/cycles/kernel/filter/filter_prefilter.h @@ -16,14 +16,19 @@ CCL_NAMESPACE_BEGIN -/* First step of the shadow prefiltering, performs the shadow division and stores all data +/** + * First step of the shadow prefiltering, performs the shadow division and stores all data * in a nice and easy rectangular array that can be passed to the NLM filter. * * Calculates: - * unfiltered: Contains the two half images of the shadow feature pass - * sampleVariance: The sample-based variance calculated in the kernel. Note: This calculation is biased in general, and especially here since the variance of the ratio can only be approximated. - * sampleVarianceV: Variance of the sample variance estimation, quite noisy (since it's essentially the buffer variance of the two variance halves) - * bufferVariance: The buffer-based variance of the shadow feature. Unbiased, but quite noisy. + * \param unfiltered: Contains the two half images of the shadow feature pass + * \param sampleVariance: The sample-based variance calculated in the kernel. + * Note: This calculation is biased in general, + * and especially here since the variance of the ratio can only be approximated. + * \param sampleVarianceV: Variance of the sample variance estimation, quite noisy + * (since it's essentially the buffer variance of the two variance halves) + * \param bufferVariance: The buffer-based variance of the shadow feature. + * Unbiased, but quite noisy. */ ccl_device void kernel_filter_divide_shadow(int sample, CCL_FILTER_TILE_INFO, @@ -204,10 +209,10 @@ ccl_device void kernel_filter_detect_outliers(int x, if (L > ref) { /* The pixel appears to be an outlier. - * However, it may just be a legitimate highlight. Therefore, it is checked how likely it is that the pixel - * should actually be at the reference value: - * If the reference is within the 3-sigma interval, the pixel is assumed to be a statistical outlier. - * Otherwise, it is very unlikely that the pixel should be darker, which indicates a legitimate highlight. + * However, it may just be a legitimate highlight. Therefore, it is checked how likely it is + * that the pixel should actually be at the reference value: If the reference is within the + * 3-sigma interval, the pixel is assumed to be a statistical outlier. Otherwise, it is very + * unlikely that the pixel should be darker, which indicates a legitimate highlight. */ if (pixel_variance < 0.0f || pixel_variance > 9.0f * max_variance) { @@ -219,7 +224,8 @@ ccl_device void kernel_filter_detect_outliers(int x, float stddev = sqrtf(pixel_variance); if (L - 3 * stddev < ref) { /* The pixel is an outlier, so negate the depth value to mark it as one. - * Also, scale its brightness down to the outlier threshold to avoid trouble with the NLM weights. */ + * Also, scale its brightness down to the outlier threshold to avoid trouble with the NLM + * weights. */ depth[idx] = -depth[idx]; float fac = ref / L; color *= fac; |