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" |
-#include "skia/ext/recursive_gaussian_convolution.h" |
- |
-namespace skia { |
- |
-namespace { |
- |
-// Takes the value produced by accumulating element-wise product of image with |
-// a kernel and brings it back into range. |
-// All of the filter scaling factors are in fixed point with kShiftBits bits of |
-// fractional part. |
-template<bool take_absolute> |
-inline unsigned char FloatTo8(float f) { |
- int a = static_cast<int>(f + 0.5f); |
- if (take_absolute) |
- a = std::abs(a); |
- else if (a < 0) |
- return 0; |
- if (a < 256) |
- return a; |
- return 255; |
-} |
- |
-template<RecursiveFilter::Order order> |
-inline float ForwardFilter(float in_n_1, |
- float in_n, |
- float in_n1, |
- const std::vector<float>& w, |
- int n, |
- const float* b) { |
- switch (order) { |
- case RecursiveFilter::FUNCTION: |
- 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) + |
- 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) + |
- b[1] * w[n-1] + b[2] * w[n-2] + b[3] * w[n-3]; |
- } |
- |
- NOTREACHED(); |
- return 0.0f; |
-} |
- |
-template<RecursiveFilter::Order order> |
-inline float BackwardFilter(const std::vector<float>& out, |
- int n, |
- float w_n, |
- float w_n1, |
- const float* b) { |
- switch (order) { |
- case RecursiveFilter::FUNCTION: |
- case RecursiveFilter::FIRST_DERIVATIVE: |
- return b[0] * w_n + |
- 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) + |
- 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( |
- const unsigned char* const source_data, |
- int source_pixel_stride, |
- int source_row_stride, |
- int row_width, |
- int row_count, |
- unsigned char* const output, |
- int output_pixel_stride, |
- int output_row_stride, |
- const float* b) { |
- const int intermediate_buffer_size = row_width + 6; |
- std::vector<float> w(intermediate_buffer_size); |
- const unsigned char* in = source_data; |
- unsigned char* out = output; |
- unsigned char max_output = 0; |
- for (int r = 0; r < row_count; |
- ++r, in += source_row_stride, out += output_row_stride) { |
- // Compute forward filter. |
- // First initialize start of the w (temporary) vector. |
- if (order == RecursiveFilter::FUNCTION) |
- w[0] = w[1] = w[2] = in[0]; |
- else |
- w[0] = w[1] = w[2] = 0.0f; |
- // Note that special-casing of w[3] is needed because of derivatives. |
- w[3] = ForwardFilter<order>( |
- in[0], in[0], in[source_pixel_stride], w, 3, b); |
- int n = 4; |
- int c = 1; |
- int byte_index = source_pixel_stride; |
- for (; c < row_width - 1; ++c, ++n, byte_index += source_pixel_stride) { |
- w[n] = ForwardFilter<order>(in[byte_index - source_pixel_stride], |
- in[byte_index], |
- in[byte_index + source_pixel_stride], |
- w, n, b); |
- } |
- |
- // The value of w corresponding to the last image pixel needs to be computed |
- // separately, again because of derivatives. |
- w[n] = ForwardFilter<order>(in[byte_index - source_pixel_stride], |
- in[byte_index], |
- in[byte_index], |
- w, n, b); |
- // Now three trailing bytes set to the same value as current w[n]. |
- w[n + 1] = w[n]; |
- w[n + 2] = w[n]; |
- w[n + 3] = w[n]; |
- |
- // Now apply the back filter. |
- float w_n1 = w[n + 1]; |
- int output_index = (row_width - 1) * output_pixel_stride; |
- for (; c >= 0; output_index -= output_pixel_stride, --c, --n) { |
- float w_n = BackwardFilter<order>(w, n, w[n], w_n1, b); |
- w_n1 = w[n]; |
- w[n] = w_n; |
- out[output_index] = FloatTo8<absolute_values>(w_n); |
- max_output = std::max(max_output, out[output_index]); |
- } |
- } |
- return max_output; |
-} |
- |
-unsigned char SingleChannelRecursiveFilter( |
- const unsigned char* const source_data, |
- int source_pixel_stride, |
- int source_row_stride, |
- int row_width, |
- int row_count, |
- unsigned char* const output, |
- int output_pixel_stride, |
- int output_row_stride, |
- const float* b, |
- RecursiveFilter::Order order, |
- bool absolute_values) { |
- if (absolute_values) { |
- switch (order) { |
- case RecursiveFilter::FUNCTION: |
- return SingleChannelRecursiveFilter<RecursiveFilter::FUNCTION, true>( |
- 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, true>( |
- source_data, source_pixel_stride, source_row_stride, |
- row_width, row_count, |
- output, output_pixel_stride, output_row_stride, b); |
- case RecursiveFilter::SECOND_DERIVATIVE: |
- return SingleChannelRecursiveFilter< |
- RecursiveFilter::SECOND_DERIVATIVE, true>( |
- 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, |
- row_width, row_count, |
- output, output_pixel_stride, output_row_stride, b); |
- case RecursiveFilter::SECOND_DERIVATIVE: |
- return SingleChannelRecursiveFilter< |
- RecursiveFilter::SECOND_DERIVATIVE, false>( |
- 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. |
- float b_norm = 1.0f - (b[1] + b[2] + b[3]) / b[0]; |
- b[1] /= b[0]; |
- 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, |
- int source_byte_row_stride, |
- int input_channel_index, |
- int input_channel_count, |
- const RecursiveFilter& filter, |
- 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, |
- input_channel_count, |
- source_byte_row_stride, |
- image_size.width(), |
- image_size.height(), |
- output + output_channel_index, |
- output_channel_count, |
- output_byte_row_stride, |
- filter.b(), |
- filter.order(), |
- absolute_values); |
-} |
- |
-unsigned char SingleChannelRecursiveGaussianY(const unsigned char* source_data, |
- int source_byte_row_stride, |
- int input_channel_index, |
- int input_channel_count, |
- const RecursiveFilter& filter, |
- 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, |
- input_channel_count, |
- image_size.height(), |
- image_size.width(), |
- output + output_channel_index, |
- output_byte_row_stride, |
- output_channel_count, |
- filter.b(), |
- filter.order(), |
- absolute_values); |
-} |
- |
-} // namespace skia |