1 files changed, 81 insertions, 0 deletions
diff --git a/python/openvino/runtime/common/demo_utils/include/utils/nms.hpp b/python/openvino/runtime/common/demo_utils/include/utils/nms.hpp
new file mode 100644
index 0000000..1fd475f
--- /dev/null
+++ b/python/openvino/runtime/common/demo_utils/include/utils/nms.hpp
@@ -0,0 +1,81 @@
+/*
+// Copyright (C) 2021-2022 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+
+#pragma once
+
+#include "opencv2/core.hpp"
+#include <numeric>
+#include <vector>
+
+struct Anchor {
+    float left;
+    float top;
+    float right;
+    float bottom;
+
+    float getWidth() const {
+        return (right - left) + 1.0f;
+    }
+    float getHeight() const {
+        return (bottom - top) + 1.0f;
+    }
+    float getXCenter() const {
+        return left + (getWidth() - 1.0f) / 2.0f;
+    }
+    float getYCenter() const {
+        return top + (getHeight() - 1.0f) / 2.0f;
+    }
+};
+
+template <typename Anchor>
+std::vector<int> nms(const std::vector<Anchor>& boxes, const std::vector<float>& scores,
+                     const float thresh, bool includeBoundaries=false) {
+    std::vector<float> areas(boxes.size());
+    for (size_t i = 0; i < boxes.size(); ++i) {
+        areas[i] = (boxes[i].right - boxes[i].left + includeBoundaries) * (boxes[i].bottom - boxes[i].top + includeBoundaries);
+    }
+    std::vector<int> order(scores.size());
+    std::iota(order.begin(), order.end(), 0);
+    std::sort(order.begin(), order.end(), [&scores](int o1, int o2) { return scores[o1] > scores[o2]; });
+
+    size_t ordersNum = 0;
+    for (; ordersNum < order.size() && scores[order[ordersNum]] >= 0; ordersNum++);
+
+    std::vector<int> keep;
+    bool shouldContinue = true;
+    for (size_t i = 0; shouldContinue && i < ordersNum; ++i) {
+        auto idx1 = order[i];
+        if (idx1 >= 0) {
+            keep.push_back(idx1);
+            shouldContinue = false;
+            for (size_t j = i + 1; j < ordersNum; ++j) {
+                auto idx2 = order[j];
+                if (idx2 >= 0) {
+                    shouldContinue = true;
+                    auto overlappingWidth = std::fminf(boxes[idx1].right, boxes[idx2].right) - std::fmaxf(boxes[idx1].left, boxes[idx2].left);
+                    auto overlappingHeight = std::fminf(boxes[idx1].bottom, boxes[idx2].bottom) - std::fmaxf(boxes[idx1].top, boxes[idx2].top);
+                    auto intersection = overlappingWidth > 0 && overlappingHeight > 0 ? overlappingWidth * overlappingHeight : 0;
+                    auto overlap = intersection / (areas[idx1] + areas[idx2] - intersection);
+
+                    if (overlap >= thresh) {
+                        order[j] = -1;
+                    }
+                }
+            }
+        }
+    }
+    return keep;
+}