Data Schema

This schema provides the structure for which all perception streams must adhere to in order to use the STREM tool, accordingly.

Overview

The schema is structured as a JSON object populated with all relevant data needed for searching over a perception stream.

Example

A valid perception data stream adhereing to the STREM format which contains a single frame where with one channel that contains two detections would look follows:

{
    "version": "1.0.0",
    "frames": [
        {
            "index": 0,
            "timestamp": 00000012342,
            "samples": [
                {
                    "channel": "cam::back",
                    "timestamp": 0000131343243423,
                    "image": {
                        "path": "images/00000.png",
                        "dimensions": {
                            "width": 640.0,
                            "height": 480.0
                        }
                    },
                    "annotations": [
                        {
                            "class": "car",
                            "score": 1.00,
                            "bbox": {
                                "x": 922.065544729849,
                                "y": 1237.456155890169,
                                "w": 259.14260407440264,
                                "h": 291.2843224092133
                            }
                        },
                        {
                            "class": "pedestrian",
                            "score": 0.76,
                            "bbox": {
                                "x": 1064.6944198405668,
                                "y": 978.3135518157661,
                                "w": 156.69087688219645,
                                "h": 146.64658990256876
                            }
                        },
                    ]
                }
            ]
        },
    ]
}

Format

The format below is separated into four distinct JSON object literals (assuming curly braces surround each block to form a syntactically valid object).

"version": str,
"frames": [ frame ]

frame

"index": int,
"timestamp": float,
"samples": [ sample ]

sample

"channel": str,
"timestamp": float,
"image": {
    "path": str,//(1)!
    "dimensions": {
        "width": float,
        "height": float
    }
},
"annotations": [ annotation ]

1. The path to the associated image is relative to the JSON file location. If no file provided, it is relative to the working directory from which the strem command was invoked.

annotation

"class": str,
"score": float,
"bbox": {
    "x": float,//(1)!
    "y": float,//(2)!
    "w": float,
    "h": float
}

1. The x coordinate represents the left-most boundary of an axis-aligned bounding box.
2. The y coordinate represents the top-most boundary of an axis-aligned bounding box.