Webcam Plot

This example will launch a webcam plot stream.

Make sure to have a webcam and cv2 install via: pip install numpy opencv-python pyarrow

Download two pre-implemented operators from our repository in a new folder webcam_project

wget https://raw.githubusercontent.com/dora-rs/dora/v0.3.2/examples/python-operator-dataflow/webcam.py
wget https://raw.githubusercontent.com/dora-rs/dora/v0.3.2/examples/python-operator-dataflow/plot.py
wget https://raw.githubusercontent.com/dora-rs/dora/v0.3.2/examples/python-operator-dataflow/utils.py

Create a new dataflow.yml file or replace the existing file with the following nodes:

nodes:
  - id: webcam
    operator:
      python: webcam.py
      inputs:
        tick: dora/timer/millis/100
      outputs:
        - image
  - id: plot
    operator:
      python: plot.py
      inputs:
        image: webcam/image

In this example, the webcam takes a tick input of frequency of 100 millis. It outputs the webcam image and dora forward it to a plot operator.

Start attached to the dataflow as follows:
```
dora start dataflow.yml --attach --hot-reload --name webcam
```
- --attach: enables you to wait for the dataflow to finish before returning.
- --hot-reload: enables you to modify Python Operator while the dataflow is running.
- --name: enables you to name a dataflow that might be simpler to use than the UUID.
You should see a small webcam window open up!

To stop your dataflow, you can use ctrl+c