rbflurry-node-red-contrib-bounding-box/README.md

A Node-RED custom node that processes and draws bounding boxes

# node-red-contrib-post-object-detection

This is a custom Node-RED node that draws bounding boxes from an Object
Detection model.

## Installation

### Prerequisite
```

This custom Node-RED node leverages the `node-canvas` npm package to draw the bounding
boxes on a image. Please make sure the platform running Node-RED fulfills the
prerequisites listed [here](https://www.npmjs.com/package/canvas#compiling). For
example, while using Ubuntu, you need to run the following command to install
the dependencies:
```
sudo apt-get install build-essential libcairo2-dev libpango1.0-dev libjpeg-dev libgif-dev librsvg2-dev
```

### Install this module:
Once you install the peer dependency and the prerequisites, you can install this module:
```
npm install node-red-contrib-post-object-detection
```

## Usage

There are two custom Node-RED nodes in this package:
- `bbox-image`: This is used to annotate an input original image with bounding boxes.


### `bbox-image` node
The `msg.payload` passed to this node should be an object containing these two
properties:
- `image`: The image data in `Buffer` data type
- `objects`: An object array containing a list of detected objects.
             Each object has the following information:
  ```
  {
    bbox: [x, y, w, h],
    className: string,
    score: number
  }
  ```

This node annotates the image by drawing the bounding boxes of detected objects onto it.
This annotated image is then output as a `Buffer` for the next node.