blender/intern/cycles/device/device_denoising.h
Lukas Stockner 740cd28748 Cycles Denoising: Add more robust outlier heuristic to avoid artifacts
Extremely bright pixels in the rendered image cause the denoising algorithm
to produce extremely noticable artifacts. Therefore, a heuristic is needed
to exclude these pixels from the filtering process.

The new approach calculates the 75% percentile of the 5x5 neighborhood of
each pixel and flags the pixel if it is more than twice as bright.

During the reconstruction process, flagged pixels are skipped. Therefore,
they don't cause any problems for neighboring pixels, and the outlier pixels
themselves are replaced by a prediction of their actual value based on their
feature pass values and the neighboring pixels.

Therefore, the denoiser now also works as a smarter despeckling filter that
uses a more accurate prediction of the pixel instead of a simple average.
This can be used even if denoising isn't wanted by setting the denoising
radius to 1.
2017-05-18 21:55:56 +02:00

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4.3 KiB
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/*
* Copyright 2011-2017 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __DEVICE_DENOISING_H__
#define __DEVICE_DENOISING_H__
#include "device/device.h"
#include "render/buffers.h"
#include "kernel/filter/filter_defines.h"
CCL_NAMESPACE_BEGIN
class DenoisingTask {
public:
/* Parameters of the denoising algorithm. */
int radius;
float nlm_k_2;
float pca_threshold;
/* Pointer and parameters of the RenderBuffers. */
struct RenderBuffers {
int denoising_data_offset;
int denoising_clean_offset;
int pass_stride;
int offset;
int stride;
device_ptr ptr;
int samples;
} render_buffer;
TilesInfo *tiles;
device_vector<int> tiles_mem;
void tiles_from_rendertiles(RenderTile *rtiles);
int4 rect;
int4 filter_area;
struct DeviceFunctions {
function<bool(device_ptr image_ptr, /* Contains the values that are smoothed. */
device_ptr guide_ptr, /* Contains the values that are used to calculate weights. */
device_ptr variance_ptr, /* Contains the variance of the guide image. */
device_ptr out_ptr /* The filtered output is written into this image. */
)> non_local_means;
function<bool(device_ptr color_ptr,
device_ptr color_variance_ptr,
device_ptr guide_ptr,
device_ptr guide_variance_ptr,
device_ptr output_ptr
)> reconstruct;
function<bool()> construct_transform;
function<bool(device_ptr a_ptr,
device_ptr b_ptr,
device_ptr mean_ptr,
device_ptr variance_ptr,
int r,
int4 rect
)> combine_halves;
function<bool(device_ptr a_ptr,
device_ptr b_ptr,
device_ptr sample_variance_ptr,
device_ptr sv_variance_ptr,
device_ptr buffer_variance_ptr
)> divide_shadow;
function<bool(int mean_offset,
int variance_offset,
device_ptr mean_ptr,
device_ptr variance_ptr
)> get_feature;
function<bool(device_ptr image_ptr,
device_ptr variance_ptr,
device_ptr depth_ptr,
device_ptr output_ptr
)> detect_outliers;
function<bool(device_ptr*)> set_tiles;
} functions;
/* Stores state of the current Reconstruction operation,
* which is accessed by the device in order to perform the operation. */
struct ReconstructionState {
device_ptr temporary_1_ptr; /* There two images are used as temporary storage. */
device_ptr temporary_2_ptr;
int4 filter_rect;
int4 buffer_params;
int source_w;
int source_h;
} reconstruction_state;
/* Stores state of the current NLM operation,
* which is accessed by the device in order to perform the operation. */
struct NLMState {
device_ptr temporary_1_ptr; /* There three images are used as temporary storage. */
device_ptr temporary_2_ptr;
device_ptr temporary_3_ptr;
int r; /* Search radius of the filter. */
int f; /* Patch size of the filter. */
float a; /* Variance compensation factor in the MSE estimation. */
float k_2; /* Squared value of the k parameter of the filter. */
void set_parameters(int r_, int f_, float a_, float k_2_) { r = r_; f = f_; a = a_, k_2 = k_2_; }
} nlm_state;
struct Storage {
device_only_memory<float> transform;
device_only_memory<int> rank;
device_only_memory<float> XtWX;
device_only_memory<float3> XtWY;
int w;
int h;
} storage;
DenoisingTask(Device *device) : device(device) {}
void init_from_devicetask(const DeviceTask &task);
bool run_denoising();
struct DenoiseBuffers {
int pass_stride;
int passes;
int w;
int h;
device_only_memory<float> mem;
} buffer;
protected:
Device *device;
};
CCL_NAMESPACE_END
#endif /* __DEVICE_DENOISING_H__ */