MLECO-2874: Move NMS out of the OD use_case
* Add ImageUtils
* Move image related code from UseCaseCommonUtils to ImageUtils
* Move NMS related code to ImageUtils
* Delete test specific ImageUtils and use new ImageUtils
Signed-off-by: Richard Burton <richard.burton@arm.com>
Change-Id: Icbf5dd9c6a941b0126ecdf69a0c9d9969f22729f
diff --git a/source/application/main/include/ImageUtils.hpp b/source/application/main/include/ImageUtils.hpp
new file mode 100644
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+++ b/source/application/main/include/ImageUtils.hpp
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+/*
+ * Copyright (c) 2022 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+#ifndef IMAGE_UTILS_HPP
+#define IMAGE_UTILS_HPP
+
+#include <cstddef>
+#include <cstdint>
+#include <forward_list>
+#include <vector>
+
+/* Helper macro to convert RGB888 to RGB565 format. */
+#define RGB888_TO_RGB565(R8,G8,B8) ((((R8>>3) & 0x1F) << 11) | \
+ (((G8>>2) & 0x3F) << 5) | \
+ ((B8>>3) & 0x1F))
+
+constexpr uint16_t COLOR_BLACK = 0;
+constexpr uint16_t COLOR_GREEN = RGB888_TO_RGB565( 0, 255, 0); // 2016;
+constexpr uint16_t COLOR_YELLOW = RGB888_TO_RGB565(255, 255, 0); // 65504;
+
+
+namespace arm {
+namespace app {
+namespace image {
+
+ /**
+ * Contains the x,y co-ordinates of a box centre along with the box width and height.
+ */
+ struct Box {
+ float x;
+ float y;
+ float w;
+ float h;
+ };
+
+ struct Detection {
+ Box bbox;
+ std::vector<float> prob;
+ float objectness;
+ };
+
+ /**
+ * @brief Calculate the 1D overlap.
+ * @param[in] x1Center First center point.
+ * @param[in] width1 First width.
+ * @param[in] x2Center Second center point.
+ * @param[in] width2 Second width.
+ * @return The overlap between the two lines.
+ **/
+ float Calculate1DOverlap(float x1Center, float width1, float x2Center, float width2);
+
+ /**
+ * @brief Calculate the intersection between the two given boxes.
+ * @param[in] box1 First box.
+ * @param[in] box2 Second box.
+ * @return The intersection value.
+ **/
+ float CalculateBoxIntersect(Box& box1, Box& box2);
+
+ /**
+ * @brief Calculate the union between the two given boxes.
+ * @param[in] box1 First box.
+ * @param[in] box2 Second box.
+ * @return The two given boxes union value.
+ **/
+ float CalculateBoxUnion(Box& box1, Box& box2);
+
+ /**
+ * @brief Calculate the intersection over union between the two given boxes.
+ * @param[in] box1 First box.
+ * @param[in] box2 Second box.
+ * @return The intersection over union value.
+ **/
+ float CalculateBoxIOU(Box& box1, Box& box2);
+
+ /**
+ * @brief Calculate the Non-Maxima suppression on the given detection boxes.
+ * @param[in] detections List of Detection boxes.
+ * @param[in] classes Number of classes.
+ * @param[in] iouThreshold Intersection over union threshold.
+ **/
+ void CalculateNMS(std::forward_list<Detection>& detections, int classes, float iouThreshold);
+
+ /**
+ * @brief Helper function to convert a UINT8 image to INT8 format.
+ * @param[in,out] data Pointer to the data start.
+ * @param[in] kMaxImageSize Total number of pixels in the image.
+ **/
+ void ConvertImgToInt8(void* data, size_t kMaxImageSize);
+
+ /**
+ * @brief Converts RGB image to grayscale.
+ * @param[in] srcPtr Pointer to RGB source image.
+ * @param[out] dstPtr Pointer to grayscale destination image.
+ * @param[in] imgSz Destination image size.
+ **/
+ void RgbToGrayscale(const uint8_t* srcPtr, uint8_t* dstPtr, size_t dstImgSz);
+
+} /* namespace image */
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* IMAGE_UTILS_HPP */
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