A bounding box in essence, is a rectangle that surrounds an object, that specifies its position, class(eg: car, person) and confidence(how likely it is to be at that location). Bounding boxes are used on object detection tasks where it is necessary to localize and classify an object in the data.
Import
Python SDK
Rectangle is a type of ObjectAnnotation
Definition
Rectangle(start = Point_top_left, end = Point_bottom_right)
| Parameter | Value |
|---|---|
start | (Point): Top left coordinate of the bounding box |
end | (Point): Bottom right coordinate of the bounding box |
Supported data types
| Data type | Supported |
|---|---|
| Image, Geospatial, Documents | Yes |
| Video | Coming soon |
bbox_xyxy = [10,10,60,110]
ObjectAnnotation(
name = "bbox_xyxy",
value = Rectangle(start = Point(x = bbox_xyxy[0], y = bbox_xyxy[1]), end = Point(x = bbox_xyxy[2], y = bbox_xyxy[3])),
)
## Coordinates in the desired EPSG coordinate system
bbox_top_left = Point(x=-99.21052827588443, y=19.405662413477728)
bbox_bottom_right = Point(x=-99.20534818927473, y=19.400498983095076)
ObjectAnnotation(
name = "bbox_geospatial",
value = Rectangle(start = bbox_top_left, end = bbox_bottom_right),
)
Format convertors
| Method | Usage | Comments |
|---|---|---|
from_xyhw() | Rectangle.from_xyhw(bbox_xyhw) | Transforms a bounding box from x,y,h,w format to x1,y1,x2,y2 format. |
from_shapely() | Rectangle.from_shapely(shapely_object) | Transforms a shapely object. If the provided shape is a non-rectangular polygon, a rectangle will be returned based on the min and max x,y values. |
bbox_xyhw = [10,10,50,100]
ObjectAnnotation(
value = Rectangle.from_xyhw(*bbox_xyhw),
name = class_name
)
from shapely.geometry import Polygon
poly = Polygon([(2, 2), (4, 4), (4, 8), (8, 8), (8, 4)])
## Converts shapely polygon object to a bounding box
ObjectAnnotation(
name = "from_shapely",
value = Rectangle.from_shapely(poly),
)
NDJSON
NDJSON format is recommended if an annotation type is not yet supported in Python SDK or if you are unable to use the Python environment.
Definition
| Parameter | Asset type | Required | Description |
|---|---|---|---|
uuid | Image, Tiled imagery, Video | Yes | A user-generated UUID for each annotation. If you import an annotation to a Data Row and there is already an imported annotation with the same uuid on that Data Row, the latest import will override the previous one. The uuid must be 128 bits (32 characters). The following formats are supported: - A0EEBC99-9C0B-4EF8-BB6D-6BB9BD380A11- {a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11}- a0eebc999c0b4ef8bb6d6bb9bd380a11- a0ee-bc99-9c0b-4ef8-bb6d-6bb9-bd38-0a11- {a0eebc99-9c0b4ef8-bb6d6bb9-bd380a11} |
schemaId | Image, Tiled imagery, Video | Yes | The ID of the schema that contains all of the information needed for rendering your annotation. |
dataRow.id | Image, Tiled imagery, Video | Yes | The ID of the Data Row where you want to attach the imported annotations. |
bbox.top | Image, Tiled imagery, Video | Yes | y-coordinate of bounding box top-left corner. |
bbox.left | Image, Tiled imagery, Video | Yes | x-coordinate of bounding box top-left corner. |
bbox.height | Image, Tiled imagery, Video | Yes | Height of bounding box in pixels. |
bbox.width | Image, Tiled imagery, Video | Yes | Width of bounding box in pixels. |
segments | Video | Yes | Segments are continuous portions of the instances track in the video. Whenever an object enters or leaves a new segment is created. |
segments.[keyframes] | Video | Yes | A segment is defined by its keyframes. Labelbox interpolates the geometry of the bounding box between key frames. As a best practice it is good to use as few key frames as possible to reduce the challenge for labelers. |
Supported data types
| Data type | Supported |
|---|---|
| Image, Video, Geospatial, Document |
Format
{
"uuid": "efca0c21-5206-4da6-8cb5-d6ca43649cfa",
"schemaId": "ck67grts29n7x0890atmeiahw",
"dataRow": {
"id": "cjxav4aa07r1g0dsq70t9eveg"
},
"bbox": {
"top": 153,
"left": 34,
"height": 204,
"width": 67
}
}
{
"uuid": "efca0c21-5206-4da6-8cb5-d6ca43649cfa",
"schemaId": "ck67grts29n7x0890atmeiahw",
"dataRow": {
"id": "cjxav4aa07r1g0dsq70t9eveg"
},
"bbox": {
"top": 153,
"left": 34,
"height": 204,
"width": 67
}
}
{
"uuid": uuid,
"schemaId": schema_id,
"dataRow": {
"id": datarow_id
},
"segments": [
{
"keyframes": [
{
"frame": 5,
"bbox": {
"top": 80,
"left": 80,
"height": 80,
"width": 80
}
},
{
"frame": 12,
"bbox": {
"top": 100,
"left": 100,
"height": 200,
"width": 100
}
},
{
"frame": 20,
"bbox": {
"top": 125,
"left": 125,
"height": 200,
"width": 300
}
}
]
},
{
"keyframes": [
{
"frame": 22,
"bbox": {
"top": 50,
"left": 50,
"height": 50,
"width": 50
}
},
{
"frame": 25,
"bbox": {
"top": 75,
"left": 75,
"height": 75,
"width": 100
}
}
]
},
{
"keyframes": [
{
"frame": 27,
"bbox": {
"top": 80,
"left": 50,
"height": 80,
"width": 50
}
}
]
}
]
}
Export
When you export your bounding Box annotations from Labelbox, the export file will contain the following information for each bounding box.
Python SDK
The export format of the bounding box is similar to the import format.
Learn more about exporting annotations using the SDK here
JSON
You will receive a JSON file when you generate an export from the app.
| Parameter | Asset type | Description |
|---|---|---|
schemaId | Image, Video, Tiled imagery, Document | The ID of the schema containing all of the information needed for rendering your annotation. |
featureId | Image, Video, Tiled imagery, Document | ID of the annotation. |
title | Image, Video, Tiled imagery, Document | Name of the annotation in the ontology. |
color | Image, Video, Tiled imagery, Document | Color of the annotation in the ontology. |
bbox.top | Image, Video, Document | y-coordinate of bounding box top-left corner. |
bbox.left | Image, Video, Document | x-coordinate of bounding box top-left corner. |
bbox.height | Image, Video, Document | Height of bounding box in pixels. |
bbox.width | Image, Video, Document | Width of bounding box in pixels. |
instanceURI | Image, Document | Annotation information hosted on Labelbox servers. |
keyframe | Video | When keyframe is true, it means that a labeler created or made an adjustment to the annotation on that frame. When keyframe is false, it means the annotation was auto-populated or interpolated on that frame. |
page | Document | The page number of that the bounding box is for |
unit | Document | Will be "POINTS" for PDF documents. Points represent 1/72 of an inch. |
type | Tiled imagery | Annotation type. Value should by rectangle. |
geometry.coordinates | Tiled imagery | Longitude and latitude, in that order. |
Format
{
"featureId": "ck9bmeej61emf0yf5bgjb4tjw",
"schemaId": "ck9blmq1lnlxw08895jy7zsk4",
"title": "Blue bird",
"value": "blue_bird",
"color": "#FF8000",
"bbox": {
"top": 186,
"left": 192,
"height": 300,
"width": 519
}
}
{
"featureId": "ck9bmeej61emf0yf5bgjb4tjw",
"schemaId": "ck9blmq1lnlxw08895jy7zsk4",
"title": "Car 1",
"value": "car_1",
"color": "#1CE6FF",
"keyframe": false,
"bbox": {
"top": 1164,
"left": 2538,
"height": 222,
"width": 119
}
}
{
"featureId": "ckossvopo00013h68phgicget",
"schemaId": "ckosstz24fhch0yag6h6k6vem",
"title": "bbox",
"value": "bbox",
"color": "#1CE6FF",
"type": "rectangle",
"geometry": {
"coordinates": [
[
[
151.20171129670584,
-33.86658193385505
],
[
151.20171129670584,
-33.86615404807865
],
[
151.20256960353075,
-33.86615404807865
],
[
151.20256960353075,
-33.86658193385505
],
[
151.20171129670584,
-33.86658193385505
]
]
]
}
}
{
"featureId": "cky8ybaew00013g67ywqyfboe",
"schemaId": "cky8xqathotfg10axdntqcja1",
"title": "Sample object 1",
"value": "sample_object_1",
"color": "#70d4e0",
"bbox": {
"top":107.442,
"left":102.326,
"height":181.116,
"width":274.232
}
"page":1,
"unit":"POINTS", // points represent 1/72 of an inch.