| Index: skia/ext/recursive_gaussian_convolution.cc
|
| diff --git a/skia/ext/recursive_gaussian_convolution.cc b/skia/ext/recursive_gaussian_convolution.cc
|
| deleted file mode 100644
|
| index 195fca8deaeaeb6bba3ccf52a6dc212c3e49ec97..0000000000000000000000000000000000000000
|
| --- a/skia/ext/recursive_gaussian_convolution.cc
|
| +++ /dev/null
|
| @@ -1,270 +0,0 @@
|
| -// Copyright (c) 2013 The Chromium Authors. All rights reserved.
|
| -// Use of this source code is governed by a BSD-style license that can be
|
| -// found in the LICENSE file.
|
| -
|
| -#include <algorithm>
|
| -#include <cmath>
|
| -#include <vector>
|
| -
|
| -#include "base/logging.h"
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| -#include "skia/ext/recursive_gaussian_convolution.h"
|
| -
|
| -namespace skia {
|
| -
|
| -namespace {
|
| -
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| -// Takes the value produced by accumulating element-wise product of image with
|
| -// a kernel and brings it back into range.
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| -// All of the filter scaling factors are in fixed point with kShiftBits bits of
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| -// fractional part.
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| -template<bool take_absolute>
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| -inline unsigned char FloatTo8(float f) {
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| - int a = static_cast<int>(f + 0.5f);
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| - if (take_absolute)
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| - a = std::abs(a);
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| - else if (a < 0)
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| - return 0;
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| - if (a < 256)
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| - return a;
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| - return 255;
|
| -}
|
| -
|
| -template<RecursiveFilter::Order order>
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| -inline float ForwardFilter(float in_n_1,
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| - float in_n,
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| - float in_n1,
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| - const std::vector<float>& w,
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| - int n,
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| - const float* b) {
|
| - switch (order) {
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| - case RecursiveFilter::FUNCTION:
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| - return b[0] * in_n + b[1] * w[n-1] + b[2] * w[n-2] + b[3] * w[n-3];
|
| - case RecursiveFilter::FIRST_DERIVATIVE:
|
| - return b[0] * 0.5f * (in_n1 - in_n_1) +
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| - b[1] * w[n-1] + b[2] * w[n-2] + b[3] * w[n-3];
|
| - case RecursiveFilter::SECOND_DERIVATIVE:
|
| - return b[0] * (in_n - in_n_1) +
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| - b[1] * w[n-1] + b[2] * w[n-2] + b[3] * w[n-3];
|
| - }
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| -
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| - NOTREACHED();
|
| - return 0.0f;
|
| -}
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| -
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| -template<RecursiveFilter::Order order>
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| -inline float BackwardFilter(const std::vector<float>& out,
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| - int n,
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| - float w_n,
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| - float w_n1,
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| - const float* b) {
|
| - switch (order) {
|
| - case RecursiveFilter::FUNCTION:
|
| - case RecursiveFilter::FIRST_DERIVATIVE:
|
| - return b[0] * w_n +
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| - b[1] * out[n + 1] + b[2] * out[n + 2] + b[3] * out[n + 3];
|
| - case RecursiveFilter::SECOND_DERIVATIVE:
|
| - return b[0] * (w_n1 - w_n) +
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| - b[1] * out[n + 1] + b[2] * out[n + 2] + b[3] * out[n + 3];
|
| - }
|
| - NOTREACHED();
|
| - return 0.0f;
|
| -}
|
| -
|
| -template<RecursiveFilter::Order order, bool absolute_values>
|
| -unsigned char SingleChannelRecursiveFilter(
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| - const unsigned char* const source_data,
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| - int source_pixel_stride,
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| - int source_row_stride,
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| - int row_width,
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| - int row_count,
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| - unsigned char* const output,
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| - int output_pixel_stride,
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| - int output_row_stride,
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| - const float* b) {
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| - const int intermediate_buffer_size = row_width + 6;
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| - std::vector<float> w(intermediate_buffer_size);
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| - const unsigned char* in = source_data;
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| - unsigned char* out = output;
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| - unsigned char max_output = 0;
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| - for (int r = 0; r < row_count;
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| - ++r, in += source_row_stride, out += output_row_stride) {
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| - // Compute forward filter.
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| - // First initialize start of the w (temporary) vector.
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| - if (order == RecursiveFilter::FUNCTION)
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| - w[0] = w[1] = w[2] = in[0];
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| - else
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| - w[0] = w[1] = w[2] = 0.0f;
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| - // Note that special-casing of w[3] is needed because of derivatives.
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| - w[3] = ForwardFilter<order>(
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| - in[0], in[0], in[source_pixel_stride], w, 3, b);
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| - int n = 4;
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| - int c = 1;
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| - int byte_index = source_pixel_stride;
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| - for (; c < row_width - 1; ++c, ++n, byte_index += source_pixel_stride) {
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| - w[n] = ForwardFilter<order>(in[byte_index - source_pixel_stride],
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| - in[byte_index],
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| - in[byte_index + source_pixel_stride],
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| - w, n, b);
|
| - }
|
| -
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| - // The value of w corresponding to the last image pixel needs to be computed
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| - // separately, again because of derivatives.
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| - w[n] = ForwardFilter<order>(in[byte_index - source_pixel_stride],
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| - in[byte_index],
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| - in[byte_index],
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| - w, n, b);
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| - // Now three trailing bytes set to the same value as current w[n].
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| - w[n + 1] = w[n];
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| - w[n + 2] = w[n];
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| - w[n + 3] = w[n];
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| -
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| - // Now apply the back filter.
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| - float w_n1 = w[n + 1];
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| - int output_index = (row_width - 1) * output_pixel_stride;
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| - for (; c >= 0; output_index -= output_pixel_stride, --c, --n) {
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| - float w_n = BackwardFilter<order>(w, n, w[n], w_n1, b);
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| - w_n1 = w[n];
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| - w[n] = w_n;
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| - out[output_index] = FloatTo8<absolute_values>(w_n);
|
| - max_output = std::max(max_output, out[output_index]);
|
| - }
|
| - }
|
| - return max_output;
|
| -}
|
| -
|
| -unsigned char SingleChannelRecursiveFilter(
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| - const unsigned char* const source_data,
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| - int source_pixel_stride,
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| - int source_row_stride,
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| - int row_width,
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| - int row_count,
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| - unsigned char* const output,
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| - int output_pixel_stride,
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| - int output_row_stride,
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| - const float* b,
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| - RecursiveFilter::Order order,
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| - bool absolute_values) {
|
| - if (absolute_values) {
|
| - switch (order) {
|
| - case RecursiveFilter::FUNCTION:
|
| - return SingleChannelRecursiveFilter<RecursiveFilter::FUNCTION, true>(
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| - source_data, source_pixel_stride, source_row_stride,
|
| - row_width, row_count,
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| - output, output_pixel_stride, output_row_stride, b);
|
| - case RecursiveFilter::FIRST_DERIVATIVE:
|
| - return SingleChannelRecursiveFilter<
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| - RecursiveFilter::FIRST_DERIVATIVE, true>(
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| - source_data, source_pixel_stride, source_row_stride,
|
| - row_width, row_count,
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| - output, output_pixel_stride, output_row_stride, b);
|
| - case RecursiveFilter::SECOND_DERIVATIVE:
|
| - return SingleChannelRecursiveFilter<
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| - RecursiveFilter::SECOND_DERIVATIVE, true>(
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| - source_data, source_pixel_stride, source_row_stride,
|
| - row_width, row_count,
|
| - output, output_pixel_stride, output_row_stride, b);
|
| - }
|
| - } else {
|
| - switch (order) {
|
| - case RecursiveFilter::FUNCTION:
|
| - return SingleChannelRecursiveFilter<RecursiveFilter::FUNCTION, false>(
|
| - source_data, source_pixel_stride, source_row_stride,
|
| - row_width, row_count,
|
| - output, output_pixel_stride, output_row_stride, b);
|
| - case RecursiveFilter::FIRST_DERIVATIVE:
|
| - return SingleChannelRecursiveFilter<
|
| - RecursiveFilter::FIRST_DERIVATIVE, false>(
|
| - source_data, source_pixel_stride, source_row_stride,
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| - row_width, row_count,
|
| - output, output_pixel_stride, output_row_stride, b);
|
| - case RecursiveFilter::SECOND_DERIVATIVE:
|
| - return SingleChannelRecursiveFilter<
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| - RecursiveFilter::SECOND_DERIVATIVE, false>(
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| - source_data, source_pixel_stride, source_row_stride,
|
| - row_width, row_count,
|
| - output, output_pixel_stride, output_row_stride, b);
|
| - }
|
| - }
|
| -
|
| - NOTREACHED();
|
| - return 0;
|
| -}
|
| -
|
| -}
|
| -
|
| -float RecursiveFilter::qFromSigma(float sigma) {
|
| - DCHECK_GE(sigma, 0.5f);
|
| - if (sigma <= 2.5f)
|
| - return 3.97156f - 4.14554f * std::sqrt(1.0f - 0.26891f * sigma);
|
| - return 0.98711f * sigma - 0.96330f;
|
| -}
|
| -
|
| -void RecursiveFilter::computeCoefficients(float q, float b[4]) {
|
| - b[0] = 1.57825f + 2.44413f * q + 1.4281f * q * q + 0.422205f * q * q * q;
|
| - b[1] = 2.4413f * q + 2.85619f * q * q + 1.26661f * q * q * q;
|
| - b[2] = - 1.4281f * q * q - 1.26661f * q * q * q;
|
| - b[3] = 0.422205f * q * q * q;
|
| -
|
| - // The above is exactly like in the paper. To cut down on computations,
|
| - // we can fix up these numbers a bit now.
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| - float b_norm = 1.0f - (b[1] + b[2] + b[3]) / b[0];
|
| - b[1] /= b[0];
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| - b[2] /= b[0];
|
| - b[3] /= b[0];
|
| - b[0] = b_norm;
|
| -}
|
| -
|
| -RecursiveFilter::RecursiveFilter(float sigma, Order order)
|
| - : order_(order), q_(qFromSigma(sigma)) {
|
| - computeCoefficients(q_, b_);
|
| -}
|
| -
|
| -unsigned char SingleChannelRecursiveGaussianX(const unsigned char* source_data,
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| - int source_byte_row_stride,
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| - int input_channel_index,
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| - int input_channel_count,
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| - const RecursiveFilter& filter,
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| - const SkISize& image_size,
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| - unsigned char* output,
|
| - int output_byte_row_stride,
|
| - int output_channel_index,
|
| - int output_channel_count,
|
| - bool absolute_values) {
|
| - return SingleChannelRecursiveFilter(source_data + input_channel_index,
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| - input_channel_count,
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| - source_byte_row_stride,
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| - image_size.width(),
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| - image_size.height(),
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| - output + output_channel_index,
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| - output_channel_count,
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| - output_byte_row_stride,
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| - filter.b(),
|
| - filter.order(),
|
| - absolute_values);
|
| -}
|
| -
|
| -unsigned char SingleChannelRecursiveGaussianY(const unsigned char* source_data,
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| - int source_byte_row_stride,
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| - int input_channel_index,
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| - int input_channel_count,
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| - const RecursiveFilter& filter,
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| - const SkISize& image_size,
|
| - unsigned char* output,
|
| - int output_byte_row_stride,
|
| - int output_channel_index,
|
| - int output_channel_count,
|
| - bool absolute_values) {
|
| - return SingleChannelRecursiveFilter(source_data + input_channel_index,
|
| - source_byte_row_stride,
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| - input_channel_count,
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| - image_size.height(),
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| - image_size.width(),
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| - output + output_channel_index,
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| - output_byte_row_stride,
|
| - output_channel_count,
|
| - filter.b(),
|
| - filter.order(),
|
| - absolute_values);
|
| -}
|
| -
|
| -} // namespace skia
|
|
|