# Module: inference/dto

## Purpose
Data transfer objects for the inference subsystem: Detection, Annotation, and a local copy of AnnotationClass/WeatherMode.

## Public Interface

### Detection
| Field | Type | Description |
|-------|------|-------------|
| `x` | float | Normalized center X |
| `y` | float | Normalized center Y |
| `w` | float | Normalized width |
| `h` | float | Normalized height |
| `cls` | int | Class ID |
| `confidence` | float | Detection confidence score |
| `overlaps(det2, iou_threshold) -> bool` | method | IoU-based overlap check |

### Annotation
| Field | Type | Description |
|-------|------|-------------|
| `frame` | numpy.ndarray | Video frame image |
| `time` | int/float | Timestamp in the video |
| `detections` | list[Detection] | Detected objects in this frame |

### AnnotationClass (duplicate)
Same as `dto/annotationClass.AnnotationClass` but with an additional `opencv_color` field (BGR tuple). Reads from `classes.json` relative to `inference/` parent directory.

### WeatherMode (duplicate)
Same as `dto/annotationClass.WeatherMode`.

## Internal Logic
- `Detection.overlaps()` computes IoU between two bounding boxes and returns True if above threshold.
- `AnnotationClass` here adds `opencv_color` as a pre-computed BGR tuple from the hex color for efficient OpenCV rendering.

## Dependencies
- `json`, `enum`, `os.path` (stdlib)

## Consumers
inference/inference

## Data Models
Detection, Annotation, AnnotationClass, WeatherMode.

## Configuration
Reads `classes.json` from project root.

## External Integrations
None.

## Security
None.

## Tests
None.