arm_compute v18.08
diff --git a/tests/validation/reference/CannyEdgeDetector.cpp b/tests/validation/reference/CannyEdgeDetector.cpp
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+/*
+ * Copyright (c) 2017-2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "CannyEdgeDetector.h"
+
+#include "Utils.h"
+#include "support/ToolchainSupport.h"
+#include "tests/validation/Helpers.h"
+#include "tests/validation/reference/Magnitude.h"
+#include "tests/validation/reference/NonMaximaSuppression.h"
+#include "tests/validation/reference/Phase.h"
+#include "tests/validation/reference/Sobel.h"
+
+#include "tests/SimpleTensorPrinter.h"
+
+#include <cmath>
+#include <stack>
+
+namespace arm_compute
+{
+namespace test
+{
+namespace validation
+{
+namespace reference
+{
+namespace
+{
+const auto MARK_ZERO = 0u;
+const auto MARK_MAYBE = 127u;
+const auto MARK_EDGE = 255u;
+
+template <typename T>
+void trace_edge(SimpleTensor<T> &dst, const ValidRegion &valid_region)
+{
+ std::stack<Coordinates> pixels_stack;
+ for(auto i = 0; i < dst.num_elements(); ++i)
+ {
+ if(dst[i] == MARK_EDGE)
+ {
+ pixels_stack.push(index2coord(dst.shape(), i));
+ }
+ }
+
+ while(!pixels_stack.empty())
+ {
+ const Coordinates pixel_coord = pixels_stack.top();
+ pixels_stack.pop();
+
+ std::array<Coordinates, 8> neighbours =
+ {
+ {
+ Coordinates(pixel_coord.x() - 1, pixel_coord.y() + 0),
+ Coordinates(pixel_coord.x() + 1, pixel_coord.y() + 0),
+ Coordinates(pixel_coord.x() - 1, pixel_coord.y() - 1),
+ Coordinates(pixel_coord.x() + 1, pixel_coord.y() + 1),
+ Coordinates(pixel_coord.x() + 0, pixel_coord.y() - 1),
+ Coordinates(pixel_coord.x() + 0, pixel_coord.y() + 1),
+ Coordinates(pixel_coord.x() + 1, pixel_coord.y() - 1),
+ Coordinates(pixel_coord.x() - 1, pixel_coord.y() + 1)
+ }
+ };
+
+ // Mark MAYBE neighbours as edges since they are next to an EDGE
+ std::for_each(neighbours.begin(), neighbours.end(), [&](Coordinates & coord)
+ {
+ if(is_in_valid_region(valid_region, coord))
+ {
+ const size_t pixel_index = coord2index(dst.shape(), coord);
+ const T pixel = dst[pixel_index];
+ if(pixel == MARK_MAYBE)
+ {
+ dst[pixel_index] = MARK_EDGE;
+ pixels_stack.push(coord);
+ }
+ }
+ });
+ }
+
+ // Mark all remaining MAYBE pixels as ZERO (not edges)
+ for(auto i = 0; i < dst.num_elements(); ++i)
+ {
+ if(dst[i] == MARK_MAYBE)
+ {
+ dst[i] = MARK_ZERO;
+ }
+ }
+}
+
+template <typename U, typename T>
+SimpleTensor<T> canny_edge_detector_impl(const SimpleTensor<T> &src, int32_t upper, int32_t lower, int gradient_size, MagnitudeType norm_type,
+ BorderMode border_mode, T constant_border_value)
+{
+ ARM_COMPUTE_ERROR_ON(gradient_size != 3 && gradient_size != 5 && gradient_size != 7);
+ ARM_COMPUTE_ERROR_ON(lower < 0 || lower >= upper);
+
+ // Output: T == uint8_t
+ SimpleTensor<T> dst{ src.shape(), src.data_type() };
+ ValidRegion valid_region = shape_to_valid_region(src.shape(), border_mode == BorderMode::UNDEFINED, BorderSize(gradient_size / 2 + 1));
+
+ // Sobel computation: U == int16_t or int32_t
+ SimpleTensor<U> gx, gy;
+ std::tie(gx, gy) = sobel<U>(src, gradient_size, border_mode, constant_border_value, GradientDimension::GRAD_XY);
+
+ using unsigned_U = typename traits::make_unsigned_conditional_t<U>::type;
+ using promoted_U = typename common_promoted_signed_type<U>::intermediate_type;
+
+ // Gradient magnitude and phase (edge direction)
+ const DataType mag_data_type = gx.data_type() == DataType::S16 ? DataType::U16 : DataType::U32;
+ SimpleTensor<unsigned_U> grad_mag{ gx.shape(), mag_data_type };
+ SimpleTensor<uint8_t> grad_dir{ gy.shape(), DataType::U8 };
+
+ for(auto i = 0; i < grad_mag.num_elements(); ++i)
+ {
+ double mag = 0.f;
+
+ if(norm_type == MagnitudeType::L2NORM)
+ {
+ mag = support::cpp11::round(std::sqrt(static_cast<promoted_U>(gx[i]) * gx[i] + static_cast<promoted_U>(gy[i]) * gy[i]));
+ }
+ else // MagnitudeType::L1NORM
+ {
+ mag = static_cast<promoted_U>(std::abs(gx[i])) + static_cast<promoted_U>(std::abs(gy[i]));
+ }
+
+ float angle = 180.f * std::atan2(static_cast<float>(gy[i]), static_cast<float>(gx[i])) / M_PI;
+ grad_dir[i] = support::cpp11::round(angle < 0.f ? 180 + angle : angle);
+ grad_mag[i] = saturate_cast<unsigned_U>(mag);
+ }
+
+ /*
+ Quantise the phase into 4 directions
+ 0° dir=0 0.0 <= p < 22.5 or 157.5 <= p < 180
+ 45° dir=1 22.5 <= p < 67.5
+ 90° dir=2 67.5 <= p < 112.5
+ 135° dir=3 112.5 <= p < 157.5
+ */
+ for(auto i = 0; i < grad_dir.num_elements(); ++i)
+ {
+ const auto direction = std::fabs(grad_dir[i]);
+ grad_dir[i] = (direction < 22.5 || direction >= 157.5) ? 0 : (direction < 67.5) ? 1 : (direction < 112.5) ? 2 : 3;
+ }
+
+ // Non-maximum suppression
+ std::vector<int> strong_edges;
+ const auto upper_thresh = static_cast<uint32_t>(upper);
+ const auto lower_thresh = static_cast<uint32_t>(lower);
+
+ const auto pixel_at_offset = [&](const SimpleTensor<unsigned_U> &tensor, const Coordinates & coord, int xoffset, int yoffset)
+ {
+ return tensor_elem_at(tensor, Coordinates{ coord.x() + xoffset, coord.y() + yoffset }, border_mode, static_cast<unsigned_U>(constant_border_value));
+ };
+
+ for(auto i = 0; i < dst.num_elements(); ++i)
+ {
+ const auto coord = index2coord(dst.shape(), i);
+ if(!is_in_valid_region(valid_region, coord) || grad_mag[i] <= lower_thresh)
+ {
+ dst[i] = MARK_ZERO;
+ continue;
+ }
+
+ unsigned_U mag_90, mag90;
+ switch(grad_dir[i])
+ {
+ case 0: // North/South edge direction, compare against East/West pixels (left & right)
+ mag_90 = pixel_at_offset(grad_mag, coord, -1, 0);
+ mag90 = pixel_at_offset(grad_mag, coord, 1, 0);
+ break;
+ case 1: // NE/SW edge direction, compare against NW/SE pixels (top-left & bottom-right)
+ mag_90 = pixel_at_offset(grad_mag, coord, -1, -1);
+ mag90 = pixel_at_offset(grad_mag, coord, +1, +1);
+ break;
+ case 2: // East/West edge direction, compare against North/South pixels (top & bottom)
+ mag_90 = pixel_at_offset(grad_mag, coord, 0, -1);
+ mag90 = pixel_at_offset(grad_mag, coord, 0, +1);
+ break;
+ case 3: // NW/SE edge direction, compare against NE/SW pixels (top-right & bottom-left)
+ mag_90 = pixel_at_offset(grad_mag, coord, +1, -1);
+ mag90 = pixel_at_offset(grad_mag, coord, -1, +1);
+ break;
+ default:
+ ARM_COMPUTE_ERROR("Invalid gradient phase provided");
+ break;
+ }
+
+ // Potential edge if greater than both pixels at +/-90° on either side
+ if(grad_mag[i] > mag_90 && grad_mag[i] > mag90)
+ {
+ // Double thresholding and edge tracing
+ if(grad_mag[i] > upper_thresh)
+ {
+ dst[i] = MARK_EDGE; // Definite edge pixel
+ strong_edges.emplace_back(i);
+ }
+ else
+ {
+ dst[i] = MARK_MAYBE;
+ }
+ }
+ else
+ {
+ dst[i] = MARK_ZERO; // Since not greater than neighbours
+ }
+ }
+
+ // Final edge tracing
+ trace_edge<T>(dst, valid_region);
+ return dst;
+}
+} // namespace
+
+template <typename T>
+SimpleTensor<T> canny_edge_detector(const SimpleTensor<T> &src, int32_t upper_thresh, int32_t lower_thresh, int gradient_size, MagnitudeType norm_type,
+ BorderMode border_mode, T constant_border_value)
+{
+ if(gradient_size < 7)
+ {
+ return canny_edge_detector_impl<int16_t>(src, upper_thresh, lower_thresh, gradient_size, norm_type, border_mode, constant_border_value);
+ }
+ else
+ {
+ return canny_edge_detector_impl<int32_t>(src, upper_thresh, lower_thresh, gradient_size, norm_type, border_mode, constant_border_value);
+ }
+}
+
+template SimpleTensor<uint8_t> canny_edge_detector(const SimpleTensor<uint8_t> &src, int32_t upper_thresh, int32_t lower_thresh, int gradient_size, MagnitudeType norm_type,
+ BorderMode border_mode, uint8_t constant_border_value);
+} // namespace reference
+} // namespace validation
+} // namespace test
+} // namespace arm_compute