perception/object/camera/docs/usecase1.md

Go to the documentation of this file.

# Copyright (c) 2017-2019 NVIDIA CORPORATION.  All rights reserved.

@page object_usecase1 Object Detector Workflow
@note SW Release Applicability: This tutorial is applicable to modules in **NVIDIA DRIVE Software** releases.

This code snippet shows how the Object Detector module is typically used. Note that error handling is left out for clarity.

Initialize ObjectDetector parameters with default values.

```{.cpp}
    dwObjectDetectorParams detectorParams{};
    dwObjectDetector_initDefaultParams(&detectorParams);
```

Modify parameters as needed.

```{.cpp}
    // Detect objects inside the full image
    detectorParams.ROIs[0] = {0, 0, imageWidth, imageHeight};
```

Initialize ObjectDetector module from DriveNet.

```{.cpp}
    initializeDriveNet();
    dwObjectDetector_initializeFromDriveNet(&detectorHandle, &detectorParameters, driveNetHandle, contextHandle);
```

Allocate a container for storing the detections. The container needs to have enough space for all
detections of all classes known to the object detector.

```{.cpp}
    dwObjectArray detections = {};
    dwObjectArray_create(&detections, 200, DW_OBJECT_TYPE_CAMERA);
```

Run all object detector processing steps on the given image.

```{.cpp}
    dwObjectDetector_detectObjects(&detections, rcbImage, detectorHandle);
```

Access the bounding boxes and classes of the detections.
```{.cpp}

    dwObjectCamera* array = static_cast<dwObjectCamera*>(detections.objects);
    for (uint32_t i = 0; i < detections.count; ++i)
    {
        // dwRectf boundingBox = array[i].box2D;
        // dwObjectClass objectClass = array[i].details.objectClass;
    }
```

To check whether depth values for the objects detected from DriveNet are available.
```{.cpp}
bool isObjectDepthEnabled;
dwObjectDetector_isObjectDepthEnabled(&isObjectDepthEnabled, detectorHandle);
```

Finally, free memory allocated by the array and the detector.

```{.cpp}
    // Free resources
    dwObjectArray_destroy(&detections);
    dwObjectDetector_release(detectorHandle);
    releaseDriveNet();
```

For more details see @ref dwx_drivenet_sample.