| /* |
| * Copyright (c) 2017-2019 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 <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{}; |
| SimpleTensor<U> 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; |
| unsigned_U 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 |