COMPMID-1849: Add DetectorPostProcess operator

Part1 - Rework of CPPNonMaximumSuppression

Change-Id: I2b34fbd12188db49b0ac050a12312494eeefd819
Signed-off-by: Isabella Gottardi <isabella.gottardi@arm.com>
Reviewed-on: https://review.mlplatform.org/c/1585
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>

2 files changed, 103 insertions, 0 deletions

diff --git a/arm_compute/core/CPP/CPPKernels.h b/arm_compute/core/CPP/CPPKernels.h
index 70d858220f..30cbf5d52c 100644
--- a/arm_compute/core/CPP/CPPKernels.h
+++ b/arm_compute/core/CPP/CPPKernels.h
@@ -29,6 +29,7 @@
 #include "arm_compute/core/CPP/kernels/CPPCornerCandidatesKernel.h"
 #include "arm_compute/core/CPP/kernels/CPPDetectionWindowNonMaximaSuppressionKernel.h"
 #include "arm_compute/core/CPP/kernels/CPPFlipWeightsKernel.h"
+#include "arm_compute/core/CPP/kernels/CPPNonMaximumSuppressionKernel.h"
 #include "arm_compute/core/CPP/kernels/CPPPermuteKernel.h"
 #include "arm_compute/core/CPP/kernels/CPPSortEuclideanDistanceKernel.h"
 #include "arm_compute/core/CPP/kernels/CPPTopKVKernel.h"
diff --git a/arm_compute/core/CPP/kernels/CPPNonMaximumSuppressionKernel.h b/arm_compute/core/CPP/kernels/CPPNonMaximumSuppressionKernel.h
new file mode 100644
index 0000000000..dd035d5cb1
--- /dev/null
+++ b/arm_compute/core/CPP/kernels/CPPNonMaximumSuppressionKernel.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 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.
+ */
+#ifndef __ARM_COMPUTE_CPP_NONMAXIMUMSUPPRESSIONKERNEL_LAYER_H__
+#define __ARM_COMPUTE_CPP_NONMAXIMUMSUPPRESSIONKERNEL_LAYER_H__
+
+#include "arm_compute/runtime/CPP/ICPPSimpleFunction.h"
+
+#include "arm_compute/core/Types.h"
+
+namespace arm_compute
+{
+class ITensor;
+
+/** CPP Function to perform non maximum suppression on the bounding boxes and scores
+ *
+ */
+class CPPNonMaximumSuppressionKernel : public ICPPKernel
+{
+public:
+    const char *name() const override
+    {
+        return "CPPNonMaximumSuppressionKernel";
+    }
+    /** Default constructor */
+    CPPNonMaximumSuppressionKernel();
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    CPPNonMaximumSuppressionKernel(const CPPNonMaximumSuppressionKernel &) = delete;
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    CPPNonMaximumSuppressionKernel &operator=(const CPPNonMaximumSuppressionKernel &) = delete;
+    /** Allow instances of this class to be moved */
+    CPPNonMaximumSuppressionKernel(CPPNonMaximumSuppressionKernel &&) = default;
+    /** Allow instances of this class to be moved */
+    CPPNonMaximumSuppressionKernel &operator=(CPPNonMaximumSuppressionKernel &&) = default;
+    /** Default destructor */
+    ~CPPNonMaximumSuppressionKernel() = default;
+
+    /** Configure the kernel to perform non maximal suppression
+     *
+     * @param[in]  input_bboxes    The input bounding boxes. Data types supported: F32.
+     * @param[in]  input_scores    The corresponding input confidence. Same as @p input_bboxes.
+     * @param[out] output_indices  The kept indices of bboxes after nms. Data types supported: S32.
+     * @param[in]  max_output_size An integer tensor representing the maximum number of boxes to be selected by non max suppression.
+     * @param[in]  score_threshold The threshold used to filter detection results.
+     * @param[in]  iou_threshold   The threshold used in non maximum suppression.
+     *
+     */
+    void configure(const ITensor *input_bboxes, const ITensor *input_scores, ITensor *output_indices, unsigned int max_output_size, const float score_threshold, const float iou_threshold);
+
+    /** Static function to check if given arguments will lead to a valid configuration of @ref CPPNonMaximumSuppressionKernel
+     *
+     * @param[in]  input_bboxes    The input bounding boxes tensor info. Data types supported: F32.
+     * @param[in]  input_scores    The corresponding input confidence tensor info. Same as @p input_bboxes.
+     * @param[out] output_indices  The kept indices of bboxes after nms tensor info. Data types supported: S32.
+     * @param[in]  max_output_size An integer tensor representing the maximum number of boxes to be selected by non max suppression.
+     * @param[in]  score_threshold The threshold used to filter detection results.
+     * @param[in]  iou_threshold   The threshold used in non maximum suppression.
+     *
+     */
+    static Status validate(const ITensorInfo *input_bboxes, const ITensorInfo *input_scores, const ITensorInfo *output_indices, unsigned int max_output_size,
+                           const float score_threshold, const float iou_threshold);
+
+    // Inherited methods overridden:
+    void run(const Window &window, const ThreadInfo &info) override;
+
+private:
+    const ITensor *_input_bboxes;
+    const ITensor *_input_scores;
+    ITensor       *_output_indices;
+    unsigned int   _max_output_size;
+    float          _score_threshold;
+    float          _iou_threshold;
+
+    unsigned int _num_boxes;
+
+    std::vector<float>        _scores_above_thd_vector;
+    std::vector<int>          _indices_above_thd_vector;
+    std::vector<bool>         _visited;
+    std::vector<unsigned int> _sorted_indices;
+};
+} // namespace arm_compute
+#endif /* __ARM_COMPUTE_CPP_NONMAXIMUMSUPPRESSIONKERNEL_LAYER_H__ */