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Cisco Meraki Documentation

How to Deploy Custom Computer Vision on MV Cameras

 

 

Documentation for Custom Computer Vision (Custom CV) that allows to deploy and run custom Machine Learning model directly on MV camera to receive objects detections beyond people & vehicle and motion detections. Here you will find hints and tips on how to get prepared and started!

Overview

Custom Computer Vision (Custom CV) allows users to deploy and run custom machine learning models directly on Cisco Meraki MV smart cameras. Use Custom CV to perform object detections that are tailored to their unique requirements.  

When you enable Custom CV on a camera, the camera disables default Meraki analytics, including motion detection, people and vehicle detection, and audio analytics. 

Refer to the Prerequisites section in this article for hardware, firmware, licensing, and other requirements.

High-level overview

The following is a high-level overview of the Custom CV workflow: 

  1. A customer or a partner develops a custom computer vision model to detect objects tailored to the business use case. Confirm that the model format complies with the requirements in the Custom Artifact Requirements section. 

  1. Enable an MV Sense license for the camera of their interest. 

  1. Use the Custom CV APIs or the Meraki dashboard UI interface to enable Custom CV and upload the model to the camera. 

  1. (Optional) Set additional parameters, such as the detection threshold. 

After the camera successfully uploads a model that meets all Custom Artifact Requirements, the camera starts model inference. To retrieve the detection output results from the camera MQTT protocol is used for communication between the device and the customer's, or partner's application. Refer to the documentation to learn more about Message Queuing Telemetry Transport (MQTT) and how to get started.

This image displays Meraki MV Sense Custom CV.

Prerequisites 

  • Hardware: Custom CV runs on all second- and third-generation MV cameras. 

  • Firmware: Networks must run MV 4.17 or later. 

  • Licensing: Custom CV requires an MV Sense license. It is available under MV Sense License. Every MV organization includes 10 free MV Sense licenses. 

  • Model limit: Custom CV runs one custom model at a time. You must enable Custom CV separately on each camera. 

Custom artifact requirements
The term artifact is used to describe a zip archive file that contains model.tflite file and an optional configuration file.

  • The artifact should be a zip archive which extracted size is no more than 40 MB

  • The artifact should contain a tflite model file which is named exactly "model.tflite"

  • The tflite model should comply with the following interface:

Inputs

Index 

Type 

Description

0

float32

A tensor representing an RGB image in NHWC order, i.e. taking the shape of [1, height, width, 3]. The tensor should represent a normalized image, where each value should be between -1 and 1.

Outputs

Index

Type

Description

0

float32

Locations. Multidimensional array of [N][4] floating point values between 0 and 1, the inner arrays representing bounding boxes in the form [top, left, bottom, right].

1

float32

Classes. Array of N integers (output as floating point values) each indicating the index of a class label

2

float32

Scores. Array of N floating point values between 0 and 1 representing probability that a class was detected.

3

float32

Number of detections. Value of N.

 

If you use the tflite converter to create a tlite model from a saved TensorFlow model, the output order may sometimes differ from what you expect. This can result in not receiving MQTT messages. To resolve this issue, try using a tflite converter version (<=2.5) or lower.

If you are unsure how to begin, use the example tflite object detection model.

Artifact packaging

  • Starter model: ssd-mobilenet-v1 - a tflite model trained on COCO dataset

  • Use any tflite model that meets the above requirements and is smaller than 40MB.

  • Rename your tflite file as "model.tflite". This is a necessary step. The camera rejects model files with other names.

  • Compress your model to a .zip archive. Place the file at the root of the archive; do not put it inside any directories when you zip it.

Step-by-step instructions 

There are two ways to get started with MV Sense Custom CV: the Meraki Dashboard UI or Custom CV APIs.

Enable Custom CV using the Meraki dashboard 

To enable MV Sense Custom CV using the dashboard, navigate to the  Settings > Sense Custom CV for the desired camera. If the Custom CV section is not visible, enable the Sense API. 

This image is displayed to guide users on enabling the MV Sense Custom CV feature in the Meraki Dashboard.

If you have not uploaded any Custom CV artifacts, complete the following steps:

1. Select Custom CV Enable button.

2. Agree to the terms and conditions

This image is displayed to assist users in enabling the Custom CV feature by clicking the Custom CV Enable button and agreeing to the terms and conditions.

3. Select add custom model.

4. Upload an artifact: provide a model name and an artifact zip file

This image is displayed to guide users on uploading a custom artifact by providing a model name and an artifact zip file.

5. Once uploaded, close the modal window.

6. Select a model from the dropdown list.

7. Optionally, you can set a detection threshold that filters detections based on prediction confidence score. Defaults to 0.5 (50%).

8. Select Save on the top right corner when artifact is successfully uploaded.

This image is displayed to guide users on saving changes after successfully uploading an artifact.

If you have already uploaded an artifact:

1. Select Custom CV Enable button.

2. Agree to the terms and conditions.

3. Choose the model from the dropdown list.

4. (Optional) Set a detection threshold that filters detections based on prediction confidence score. Defaults to 0.5 (50%).

5. Select Save on the top right corner.

This image is displayed to guide users on saving changes.

Enable Custom CV using the dashboard API 

To get started with API please refer to the API documentation which is accessible through Dashboard > Help > API docs Custom CV section.

To use the API, you need both the Dashboard API Key and the Organization ID.

All MV cameras provide an MQTT client to retrieve detection outputs. If you are not familiar with MQTT, refer to the documentation to learn more about protocol and how to enable it for your organization.

To receive detection outputs from camera subscribe to the topic below from your MQTT broker. 

`/merakimv/<DEVICE_SERIAL>/custom_analytics`

Example MQTT message:

{
    "outputs":
        [{
            "class":0,
            "id":123,
            "location":[0.1,0.2,0.4,0.3],
            "score":0.7
         }],
     "timestamp":1646175500000
}

Outputs: An array of detected objects

Detections: Each detection represents a detected object that has its object class type, detection id, location coordinates [left, top, right, bottom] or [x0,y0,x1,y1] and probability score.

Timestamp: time & date when detections occur

Configure Custom CV webhooks

Custom CV webhooks let you receive real-time custom model detections and camera frames from your MV cameras. Custom CV webhooks extend the capabilities of Meraki cloud webhooks.

Key concepts

Before you configure Custom CV webhooks, review the following key concepts:

  1. Webhook: An HTTP callback or POST request that is triggered by specific events or data changes in your Meraki network. When an event occurs, Meraki sends an HTTP request to a customer owned specified URL (webhook receiver) with relevant data, allowing you to respond to the event programmatically.

  2. Custom payload template: Webhooks in Meraki require you to provide a custom payload template in the webhook server configuration. This template defines the structure of the data you will receive in your webhook message. While creating the template, you will use Liquid template tags and filters to format the data.

  3. Liquid template: Liquid is a lightweight templating language used to generate dynamic content in web pages and, in this case, in webhook payloads. In Meraki, you can use Liquid tags and filters to access and manipulate data from events.

Configuration Steps

To configure Custom CV webhooks, complete the following steps:

Configure a Webhook Service: In the Meraki dashboard, navigate to Network-wide > Configure > Alerts > Webhooks. Configure the webhook service, define the events to monitor, and set the URL where Meraki sends webhook data.

Create a Custom Payload Template: Select Add or edit webhook templates to create a custom payload template, then select Save. This template determines how Meraki formats the data sent to your webhook receiver.

Using the Add or edit webhook templates option to create custom payload templates via the dashboard UI is only available if you opt in to Early API Access at Organization > Configure > Early Access. If you do not want to opt-in, create a custom payload template using a webhook API instead.

 

Custom payload template example:

{
    "device": "{{ deviceSerial }}",
    "data": {{ alertData | jsonify }}
}

 

Configure Custom CV Webhook: Select Add an Https Receiver, then provide all necessary information, for example a name, and select the custom template. (Optional): To ensure that your webhook is properly configured, you can use the "Send test webhook" feature to send a test event to your webhook receiver URL.

Configure Webhook on Camera: To enable webhooks on the device you need to use the Custom CV Webhook API.

Parameter Name Value

X-Cisco-Meraki-API-Key (Header)

Meraki Dashboard API KEY

Replace $MERAKI_DASHBOARD_API_KEY in examples below



artifactId

Custom CV artifact ID

(This can be found in Dashboard, MV Sense under "Add or Delete Custom Models", or by using the /organizations/{organizationId}/camera/customAnalytics/artifacts API Endpoint)

Replace $ARTIFACT_ID in examples below

detection_threshold

 

artifact detection threshold

Replace $DETECTION_THRESHOLD in examples below

dev_output_webhook_server

Use the following API to receive retrieve a webhook ID, for that you will need to have a Network ID.

Replace $WEBHOOK_ID in examples below

dev_output_enable_snapshot_end_time

Expiration date "YYYY-MM-DD" for sending camera detection frames, can be set to max 7 days starting from the date of configuration

Replace $EXPIRATION_DATE in examples below

dev_output_json_filter Set to:
{\"type\":\"object\"}

To customise this further, view the "How do I manage filters?" section below.

 

The following is an example command to set these parameters, you need to substitute the parameter values with your own:

cURL
curl -s -H "Content-Type: application/json" \
    -H "Accept: application/json" \
    -H "X-Cisco-Meraki-API-Key: $MERAKI_DASHBOARD_API_KEY" \
    -d '{"enabled":true,"artifactId":"$ARTIFACT_ID","parameters":[\
   {"name":"detection_threshold","value":$DETECTION_THRESHOLD},\
     {"name":"dev_output_webhook_server","value":"$WEBHOOK_ID"},\
     {"name":"dev_output_enable_snapshot_end_time","value":"$EXPIRATION_DATE"},\
     {"name":"dev_output_json_filter","value":"{\"type\":\"object\"}"}]}'\
    -X PUT "https://api.meraki.com/api/v1/devices/$DEVICE_SERIAL/camera/customAnalytics
Python Requests
import requests
import json

merakiHeaders = {"X-Cisco-Meraki-API-Key": "$MERAKI_DASHBOARD_API_KEY", "Content-Type": "application/json"}

ciBody = {
    "enabled": True,
    "artifactId": "$ARTIFACT_ID",
    "parameters": [
        {
            "name": "detection_threshold",
            "value": $DETECTION_THRESHOLD
        },
        {
            "name": "dev_output_webhook_server",
            "value": $WEBHOOK_ID
        },
        {
            "name": "dev_output_enable_snapshot_end_time",
            "value": $EXPIRATION_DATE
        },
        {
            "name": "dev_output_json_filter",
            "value": "{\"type\":\"object\"}"
        }
    ]
}
res = requests.put(url=f"https://api.meraki.com/api/v1/devices/$DEVICE_SERIAL/camera/customAnalytics", headers=merakiHeaders, data=json.dumps(ciBody))

Making this request will modify the Camera's MV Sense settings on the Dashboard. Any changes made to the Camera's Sense Settings on the Dashboard will currently remove the Webhook Server configuration from the camera.

Example of payload body received by the server (based on the template above)

{
  "serial": "XXXX-YYYY-ZZZZ",
  "mac": "00:00:00:00:00:00",
  "data": {
    "outputs": [
      {
        "class": 0,
        "id": 1,
        "location": [
          0.422,
          0.363,
          0.508,
          0.623
        ],
        "score": 0.344
      }
    ],
    "snapshot": "data:image/jpeg;base64,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",
    "timestamp": 1686669655302
  }
}

The data received is dependent on the configured webhook server. Example above does not include the entire encoded base64 image.

 

Manage detection filters

Provide your Meraki representative with a filter JSON schema; they will update the camera configuration for you.

Refer to the https://json-schema.org/ to learn more about supported json schema version is draft v4.

 

Example json schema

This example schema passes when all detected objects in a frame have a score less than 0.9:

 {
    "type": "object",
    "properties": {
        "outputs": {
            "type": "array",
            "items": {
                "type": "object",
                "properties": {
                    "Score": {
                        "Type": "number",
                        "Maximum": 0.9
                    }
                }
            }
        }
    }
}

Example json schema in payload

This is the above example schema when formatted for the API request:

{
    "name": "dev_output_json_filter",
    "value": "{\"type\":\"object\",\"properties\":{\"outputs\":{\"type\":\"array\",\"items\":{\"type\":\"object\",\"properties\":{\"Score\":{\"Type\":\"number\",\"Maximum\":0.9}}}}}}"
}

 

Example result for filtering 

{
    "outputs": [
        {
            "class": 0,
            "id": 1,
            "location": [
                0.422,
                0.363,
                0.508,
                0.623
            ],
            "score": 0.344
        }
    ],
    "timestamp": 1686669655302
}

Custom CV artifacts uploads are failing

1. We allow only .zip files that contain only "model.tflite" file inside. Check .zip file for any other foreign files e.g. ".DS_store" and remove them. Try uploading again.

2. Review the error message that appears during the upload. Confirm that you built the model using an approved tflite version listed in the document above, and that the model input and outputs meet the custom artifact requirements.

Custom CV models are not available for selection

Confirm your custom artifact has been successfully uploaded to your artifact store. You can observe this by either using the Dashboard API to GET all custom artifacts or by viewing the "Add or delete custom models" on the Custom CV subsection of your camera settings' Sense subtab.

Where to find Custom CV models, Add or Delete

Before contacting support, verify the following cases:

1. The camera detects some objects but not all objects. Refer to the Custom CV Model Performance Issues section for more information.

2. The camera is connected to an MQTT broker, but the broker does not receive any detections. Misconfigured MQTT broker settings or network restrictions can cause this issue.

Custom CV model performance issues

If there is an issue with model performance (for example, object detections are inconsistent, detections are slow, object tracking is poor), Meraki Support cannot assist with these matters directly. Consult the documentation of your Custom CV developer or provider, or contact their support directly. If you are using a service from a Cisco SolutionsPlus provider, refer to the following section.

Troubleshooting  

Support for Cisco SolutionsPlus Offerings for Custom CV

The following section lists contact details for Custom CV offerings available through Cisco SolutionsPlus vendors. For model performance issues, review the vendor's documentation or contact their support team. For Custom CV service issues, review the Troubleshooting section in this article and contact Meraki Support for further assistance.

Cogniac

Cogniac logo

Cogniac provides a simple, no-code platform for customers to easily define and deploy their own custom object detection with as few as 50 images to start. To learn more, visit their product page here.

Regions supported: America, EMEA, APJC, LATAM

·   Support Email AddressSupport@cogniac.co

    160 W Santa Clara St, San Jose, CA 95113

·   Support Phone Number:

     +1 (888) 634-7483

     +1 (805) 392 9976

·   Support Hours:

  24 X 7 (round the clock support)

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