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Diffstat (limited to 'arm_compute/core/NEON/kernels/NEHistogramKernel.h')
| -rw-r--r-- | arm_compute/core/NEON/kernels/NEHistogramKernel.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arm_compute/core/NEON/kernels/NEHistogramKernel.h b/arm_compute/core/NEON/kernels/NEHistogramKernel.h new file mode 100644 index 0000000000..c4dbbeae83 --- /dev/null +++ b/arm_compute/core/NEON/kernels/NEHistogramKernel.h @@ -0,0 +1,129 @@ +/* + * Copyright (c) 2016, 2017 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. + */ +#ifndef __ARM_COMPUTE_NEHISTOGRAMKERNEL_H__ +#define __ARM_COMPUTE_NEHISTOGRAMKERNEL_H__ + +#include "arm_compute/core/NEON/INEKernel.h" + +#include <cstddef> +#include <cstdint> +#include <mutex> + +namespace arm_compute +{ +class IDistribution1D; +class ITensor; +using IImage = ITensor; + +/** Interface for the histogram kernel */ +class NEHistogramKernel : public INEKernel +{ +public: + /** Default constructor */ + NEHistogramKernel(); + /** Default destructor */ + ~NEHistogramKernel() = default; + /** Prevent instances of this class from being copied (As this class contains pointers) */ + NEHistogramKernel(const NEHistogramKernel &) = delete; + /** Prevent instances of this class from being copied (As this class contains pointers) */ + NEHistogramKernel &operator=(const NEHistogramKernel &) = delete; + /** Allow instances of this class to be moved */ + NEHistogramKernel(NEHistogramKernel &&) = default; + /** Allow instances of this class to be moved */ + NEHistogramKernel &operator=(NEHistogramKernel &&) = default; + + /** Set the input image and the distribution output. + * + * @param[in] input Source image. Data type supported: U8. + * @param[out] output Destination distribution. + * @param[in,out] local_hist Array that the threads use to save their local histograms. + * It's size should be equal to (number_of_threads * num_bins), + * and the Window::thread_id() is used to determine the part of the array + * used by each thread. + * @param[out] window_lut LUT with pre-calculated possible window values. + * The size of the LUT should be equal to max_range_size and it will be filled + * during the configure stage, while it re-used in every run, therefore can be + * safely shared among threads. + */ + void configure(const IImage *input, IDistribution1D *output, uint32_t *local_hist, uint32_t *window_lut); + /** Set the input image and the distribution output. + * + * @note Used for histogram of fixed size equal to 256 + * + * @param[in] input Source image. Data type supported: U8. + * @param[out] output Destination distribution which must be of 256 bins.. + */ + void configure(const IImage *input, IDistribution1D *output); + + // Inherited methods overridden: + void run(const Window &window) override; + +private: + /** Function to merge multiple partial histograms. + * + * @param[out] global_hist Pointer to the final histogram. + * @param[in] local_hist Pointer to the partial histograms. + * @param[in] bins Number of bins. + */ + void merge_histogram(uint32_t *global_hist, const uint32_t *local_hist, size_t bins); + /** Function to merge multiple minimum values of partial histograms. + * + * @param[out] global_min Pointer to the global min value. + * @param[in] local_min Local min value. + */ + void merge_min(uint8_t *global_min, const uint8_t &local_min); + /** Function to perform histogram on the given window + * + * @param[in] win Region on which to execute the kernel + */ + void histogram_U8(Window win); + /** Function to perform histogram on the given window where histogram is + * of fixed size 256 without ranges and offsets. + * + * @param[in] win Region on which to execute the kernel + */ + void histogram_fixed_U8(Window win); + /** Pre-calculate the pixel windowing for every possible pixel + * + * Calculate (V - offset) * numBins / range where V is every possible pixel value. + * + * @note We currently support U8 image thus possible pixel values are between 0 and 255 + */ + void calculate_window_lut() const; + /** Common signature for all the specialised Histogram functions + * + * @param[in] window Region on which to execute the kernel. + */ + using HistogramFunctionPtr = void (NEHistogramKernel::*)(Window window); + + HistogramFunctionPtr _func; ///< Histogram function to use for the particular image types passed to configure() + const IImage *_input; + IDistribution1D *_output; + uint32_t *_local_hist; + uint32_t *_window_lut; + std::mutex _hist_mtx; + static constexpr unsigned int _max_range_size{ 256 }; ///< 256 possible pixel values as we handle only U8 images +}; +} +#endif /*__ARM_COMPUTE_NEHISTOGRAMKERNEL_H__ */ |