104 lines
3.7 KiB
C++
104 lines
3.7 KiB
C++
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// ======================================================================== //
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// Copyright 2009-2019 Intel Corporation //
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// //
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// Licensed under the Apache License, Version 2.0 (the "License"); //
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// you may not use this file except in compliance with the License. //
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// You may obtain a copy of the License at //
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// //
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// http://www.apache.org/licenses/LICENSE-2.0 //
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// //
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// Unless required by applicable law or agreed to in writing, software //
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// distributed under the License is distributed on an "AS IS" BASIS, //
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. //
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// See the License for the specific language governing permissions and //
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// limitations under the License. //
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// ======================================================================== //
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#include "transfer_function.h"
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namespace oidn {
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const float LogTransferFunction::xScale = 1.f / log(LogTransferFunction::yMax + 1.f);
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const float PQXTransferFunction::xScale = 1.f / PQXTransferFunction::pqxForward(PQXTransferFunction::yMax * PQXTransferFunction::yScale);
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float AutoexposureNode::autoexposure(const Image& color)
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{
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assert(color.format == Format::Float3);
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constexpr float key = 0.18f;
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constexpr float eps = 1e-8f;
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constexpr int K = 16; // downsampling amount
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// Downsample the image to minimize sensitivity to noise
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const int H = color.height; // original height
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const int W = color.width; // original width
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const int HK = (H + K/2) / K; // downsampled height
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const int WK = (W + K/2) / K; // downsampled width
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// Compute the average log luminance of the downsampled image
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using Sum = std::pair<float, int>;
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// -- GODOT start --
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// Sum sum =
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// tbb::parallel_reduce(
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// tbb::blocked_range2d<int>(0, HK, 0, WK),
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// Sum(0.f, 0),
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// [&](const tbb::blocked_range2d<int>& r, Sum sum) -> Sum
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// {
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// // Iterate over blocks
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// for (int i = r.rows().begin(); i != r.rows().end(); ++i)
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// {
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// for (int j = r.cols().begin(); j != r.cols().end(); ++j)
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// {
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Sum sum = Sum(0.0f, 0);
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for (int i = 0; i != HK; ++i)
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{
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for (int j = 0; j != WK; ++j)
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{
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// Compute the average luminance in the current block
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const int beginH = int(ptrdiff_t(i) * H / HK);
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const int beginW = int(ptrdiff_t(j) * W / WK);
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const int endH = int(ptrdiff_t(i+1) * H / HK);
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const int endW = int(ptrdiff_t(j+1) * W / WK);
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float L = 0.f;
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for (int h = beginH; h < endH; ++h)
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{
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for (int w = beginW; w < endW; ++w)
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{
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const float* rgb = (const float*)color.get(h, w);
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const float r = maxSafe(rgb[0], 0.f);
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const float g = maxSafe(rgb[1], 0.f);
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const float b = maxSafe(rgb[2], 0.f);
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L += luminance(r, g, b);
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}
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}
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L /= (endH - beginH) * (endW - beginW);
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// Accumulate the log luminance
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if (L > eps)
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{
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sum.first += log2(L);
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sum.second++;
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}
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}
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}
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// return sum;
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// },
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// [](Sum a, Sum b) -> Sum { return Sum(a.first+b.first, a.second+b.second); },
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// tbb::static_partitioner()
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// );
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// -- GODOT end --
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return (sum.second > 0) ? (key / exp2(sum.first / float(sum.second))) : 1.f;
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}
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} // namespace oidn
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