Method GetVisibleObjects

src/effects/ObjectDetection.cpp:254–307

Get the indexes and IDs of all visible objects in the given frame

// Get the indexes and IDs of all visible objects in the given frame
std::string ObjectDetection::GetVisibleObjects(int64_t frame_number) const{

	// Initialize the JSON objects
	Json::Value root;
	root["visible_objects_index"] = Json::Value(Json::arrayValue);
	root["visible_objects_id"] = Json::Value(Json::arrayValue);
    root["visible_class_names"] = Json::Value(Json::arrayValue);

	// Check if track data exists for the requested frame
	if (detectionsData.find(frame_number) == detectionsData.end()){
		return root.toStyledString();
	}
	DetectionData detections = detectionsData.at(frame_number);

	// Iterate through the tracked objects
	for(int i = 0; i<detections.boxes.size(); i++){
		// Does not show boxes with confidence below the threshold
		if(detections.confidences.at(i) < confidence_threshold){
			continue;
		}

		// Get class name of tracked object
        auto className = classNames[detections.classIds.at(i)];

        // If display_classes is not empty, check if className is in it
        if (!display_classes.empty()) {
            auto it = std::find(display_classes.begin(), display_classes.end(), className);
            if (it == display_classes.end()) {
                // If not in display_classes, skip this detection
                continue;
            }
            root["visible_class_names"].append(className);
        } else {
            // include all class names
            root["visible_class_names"].append(className);
        }

		int objectId = detections.objectIds.at(i);
		// Search for the object in the trackedObjects map
		auto trackedObject = trackedObjects.find(objectId);

		// Get the tracked object JSON properties for this frame
		Json::Value trackedObjectJSON = trackedObject->second->PropertiesJSON(frame_number);

		if (trackedObjectJSON["visible"]["value"].asBool() &&
			trackedObject->second->ExactlyContains(frame_number)){
			// Save the object's index and ID if it's visible in this frame
			root["visible_objects_index"].append(trackedObject->first);
			root["visible_objects_id"].append(trackedObject->second->Id());
		}
	}

	return root.toStyledString();
}

// Generate JSON string of this object
std::string ObjectDetection::Json() const {