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  • IMU and Video Sync
  • Similar samples:
  • Demo
  • Setup
  • Source code
  • How it Works

IMU and Video Sync

This example demonstrates the use of the DepthAI Sync node to synchronize IMU (Inertial Measurement Unit) data with video frames from a color camera. It highlights the capability to process and display the latest rotation vector from the IMU alongside the video stream in real-time.

Similar samples:

Demo

Command Line
1~/depthai-python/examples/Sync $ python3 imu_video_synced.py
2IMU type: BNO086, firmware version: 3.9.7
3
4Device timestamp imu: 0:00:05.379914
5Device timestamp video:0:00:05.385096
6Quaternion: i: -0.0549 j: -0.0335 k: 0.0018 real: 0.9979
7
8
9Device timestamp imu: 0:00:05.410274
10Device timestamp video:0:00:05.418425
11Quaternion: i: -0.0549 j: -0.0334 k: 0.0018 real: 0.9979
12
13
14Device timestamp imu: 0:00:05.445439
15Device timestamp video:0:00:05.451753
16Quaternion: i: -0.0548 j: -0.0334 k: 0.0018 real: 0.9979
17
18
19Device timestamp imu: 0:00:05.475084
20Device timestamp video:0:00:05.485082
21Quaternion: i: -0.0547 j: -0.0334 k: 0.0018 real: 0.9979
22
23
24Device timestamp imu: 0:00:05.510046
25Device timestamp video:0:00:05.518411
26Quaternion: i: -0.0546 j: -0.0334 k: 0.0018 real: 0.9979

Setup

Please run the install script to download all required dependencies. Please note that this script must be ran from git context, so you have to download the depthai-python repository first and then run the script
Command Line
1git clone https://github.com/luxonis/depthai-python.git
2cd depthai-python/examples
3python3 install_requirements.py
For additional information, please follow the installation guide.

Source code

Python
C++

Python

Python
GitHub
1import depthai as dai
2import numpy as np
3import cv2
4from datetime import timedelta
5
6device = dai.Device()
7
8imuType = device.getConnectedIMU()
9imuFirmwareVersion = device.getIMUFirmwareVersion()
10print(f"IMU type: {imuType}, firmware version: {imuFirmwareVersion}")
11
12if imuType != "BNO086":
13    print("Rotation vector output is supported only by BNO086!")
14    exit(0)
15
16pipeline = dai.Pipeline()
17
18color = pipeline.create(dai.node.ColorCamera)
19imu = pipeline.create(dai.node.IMU)
20sync = pipeline.create(dai.node.Sync)
21xoutImu = pipeline.create(dai.node.XLinkOut)
22xoutImu.setStreamName("imu")
23
24xoutGrp = pipeline.create(dai.node.XLinkOut)
25xoutGrp.setStreamName("xout")
26
27color.setCamera("color")
28
29imu.enableIMUSensor(dai.IMUSensor.ROTATION_VECTOR, 120)
30imu.setBatchReportThreshold(1)
31imu.setMaxBatchReports(10)
32
33sync.setSyncThreshold(timedelta(milliseconds=10))
34sync.setSyncAttempts(-1)
35
36color.video.link(sync.inputs["video"])
37imu.out.link(sync.inputs["imu"])
38
39sync.out.link(xoutGrp.input)
40
41
42with device:
43    device.startPipeline(pipeline)
44    groupQueue = device.getOutputQueue("xout", 3, True)
45    while True:
46        groupMessage = groupQueue.get()
47        imuMessage = groupMessage["imu"]
48        colorMessage = groupMessage["video"]
49        print()
50        print("Device timestamp imu: " + str(imuMessage.getTimestampDevice()))
51        print("Device timestamp video:" + str(colorMessage.getTimestampDevice()))
52        latestRotationVector = imuMessage.packets[-1].rotationVector
53        imuF = "{:.4f}"
54        print(f"Quaternion: i: {imuF.format(latestRotationVector.i)} j: {imuF.format(latestRotationVector.j)} "
55        f"k: {imuF.format(latestRotationVector.k)} real: {imuF.format(latestRotationVector.real)}")
56        print()
57        cv2.imshow("video", colorMessage.getCvFrame())
58        if cv2.waitKey(1) == ord("q"):
59            break

How it Works

  • Initialize the DepthAI device.
  • Check the connected IMU type and firmware version.
  • Create a pipeline and add a ColorCamera and IMU node.
  • Set up the Sync node to synchronize the IMU data with the video frames.
  • Link the output of the ColorCamera and IMU nodes to the Sync node.
  • Start the pipeline and continuously receive synchronized data.
  • Display the video frames and print the IMU rotation vector data, including quaternion values.

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