Helper - DepthAI as a generator

If you want to integrate the DepthAI into your project, this example might be useful for you as it splits the “how to get the results”, from “what to do with them”.

This example uses yield keyword to send the results to for loop, which called the method.

It’s useful if you want to process the received frames further in your custom code

Code

import cv2
import depthai


class DepthAI:
    def __init__(self):
        self.device = depthai.Device('', False)

        self.p = self.device.create_pipeline(config={
            "streams": ["metaout", "previewout"],
            "ai": {
                "blob_file": "/path/to/model.blob",
                "blob_file_config": "/path/to/config.json"
            }
        })

        self.detections = []

    def run(self):
        while True:
            nnet_packets, data_packets = self.p.get_available_nnet_and_data_packets()

            for nnet_packet in nnet_packets:
                self.detections = list(nnet_packet.getDetectedObjects())

            for packet in data_packets:
                if packet.stream_name == 'previewout':
                    data = packet.getData()
                    data0 = data[0, :, :]
                    data1 = data[1, :, :]
                    data2 = data[2, :, :]
                    frame = cv2.merge([data0, data1, data2])

                    img_h = frame.shape[0]
                    img_w = frame.shape[1]

                    results = []
                    for detection in self.detections:
                        pt1 = int(detection.x_min * img_w), int(detection.y_min * img_h)
                        pt2 = int(detection.x_max * img_w), int(detection.y_max * img_h)
                        results.append((pt1, pt2))
                    yield frame, results

    def __del__(self):
        del self.p
        del self.device


d = DepthAI()

for frame, results in d.run():
    for pt1, pt2 in results:
        cv2.rectangle(frame, pt1, pt2, (0, 0, 255), 2)
    cv2.imshow('previewout', frame)

    if cv2.waitKey(1) == ord('q'):
        break

del d

Got questions?

We’re always happy to help with code or other questions you might have.