[PolygonZone] - allow per class counting

[SkalskiP]

Description

Currently, sv.PolygonZone provides only current aggregated counts - all classes are thrown into one bucket. In the past, many users have asked us to provide more granular - per class count. This can be achieved by adding class_in_count and class_out_count dictionaries that will store per-class counts.

class PolygonZone:

    def __init__(
        self,
        polygon: np.ndarray,
        frame_resolution_wh: Tuple[int, int],
        triggering_position: Position = Position.BOTTOM_CENTER,
    ):
        # Existing initialization code...

        self.class_in_count: Dict[int, int] = {}
        self.class_out_count: Dict[int, int] = {}

    def trigger(self, detections: Detections) -> np.ndarray:
        crossed_in = np.full(len(detections), False)
        crossed_out = np.full(len(detections), False)

        # Required logic changes...

Additional

• Note: Please share a Google Colab with minimal code to test the new feature. We know it's additional work, but it will definitely speed up the review process. Each change must be tested by the reviewer. Setting up a local environment to do this is time-consuming. Please ensure that Google Colab can be accessed without any issues (make it public). Thank you! 🙏🏻

[karanjakhar]

Hi @SkalskiP I would like to work on it.

[SkalskiP]

Hi @karanjakhar 👋🏻 ! Sure, I assigned the issue to you. Have fun! 🔥