Spaces:
Running
on
Zero
Running
on
Zero
File size: 5,288 Bytes
b213d84 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 |
#!/usr/bin/env python3
# Copyright 2004-present Facebook. All Rights Reserved.
import numpy as np
from typing import List
from detectron2.config import CfgNode as CfgNode_
from detectron2.config import configurable
from detectron2.structures import Instances
from detectron2.structures.boxes import pairwise_iou
from detectron2.tracking.utils import LARGE_COST_VALUE, create_prediction_pairs
from .base_tracker import TRACKER_HEADS_REGISTRY
from .hungarian_tracker import BaseHungarianTracker
@TRACKER_HEADS_REGISTRY.register()
class VanillaHungarianBBoxIOUTracker(BaseHungarianTracker):
"""
Hungarian algo based tracker using bbox iou as metric
"""
@configurable
def __init__(
self,
*,
video_height: int,
video_width: int,
max_num_instances: int = 200,
max_lost_frame_count: int = 0,
min_box_rel_dim: float = 0.02,
min_instance_period: int = 1,
track_iou_threshold: float = 0.5,
**kwargs,
):
"""
Args:
video_height: height the video frame
video_width: width of the video frame
max_num_instances: maximum number of id allowed to be tracked
max_lost_frame_count: maximum number of frame an id can lost tracking
exceed this number, an id is considered as lost
forever
min_box_rel_dim: a percentage, smaller than this dimension, a bbox is
removed from tracking
min_instance_period: an instance will be shown after this number of period
since its first showing up in the video
track_iou_threshold: iou threshold, below this number a bbox pair is removed
from tracking
"""
super().__init__(
video_height=video_height,
video_width=video_width,
max_num_instances=max_num_instances,
max_lost_frame_count=max_lost_frame_count,
min_box_rel_dim=min_box_rel_dim,
min_instance_period=min_instance_period,
)
self._track_iou_threshold = track_iou_threshold
@classmethod
def from_config(cls, cfg: CfgNode_):
"""
Old style initialization using CfgNode
Args:
cfg: D2 CfgNode, config file
Return:
dictionary storing arguments for __init__ method
"""
assert "VIDEO_HEIGHT" in cfg.TRACKER_HEADS
assert "VIDEO_WIDTH" in cfg.TRACKER_HEADS
video_height = cfg.TRACKER_HEADS.get("VIDEO_HEIGHT")
video_width = cfg.TRACKER_HEADS.get("VIDEO_WIDTH")
max_num_instances = cfg.TRACKER_HEADS.get("MAX_NUM_INSTANCES", 200)
max_lost_frame_count = cfg.TRACKER_HEADS.get("MAX_LOST_FRAME_COUNT", 0)
min_box_rel_dim = cfg.TRACKER_HEADS.get("MIN_BOX_REL_DIM", 0.02)
min_instance_period = cfg.TRACKER_HEADS.get("MIN_INSTANCE_PERIOD", 1)
track_iou_threshold = cfg.TRACKER_HEADS.get("TRACK_IOU_THRESHOLD", 0.5)
return {
"_target_": "detectron2.tracking.vanilla_hungarian_bbox_iou_tracker.VanillaHungarianBBoxIOUTracker", # noqa
"video_height": video_height,
"video_width": video_width,
"max_num_instances": max_num_instances,
"max_lost_frame_count": max_lost_frame_count,
"min_box_rel_dim": min_box_rel_dim,
"min_instance_period": min_instance_period,
"track_iou_threshold": track_iou_threshold,
}
def build_cost_matrix(self, instances: Instances, prev_instances: Instances) -> np.ndarray:
"""
Build the cost matrix for assignment problem
(https://en.wikipedia.org/wiki/Assignment_problem)
Args:
instances: D2 Instances, for current frame predictions
prev_instances: D2 Instances, for previous frame predictions
Return:
the cost matrix in numpy array
"""
assert instances is not None and prev_instances is not None
# calculate IoU of all bbox pairs
iou_all = pairwise_iou(
boxes1=instances.pred_boxes,
boxes2=self._prev_instances.pred_boxes,
)
bbox_pairs = create_prediction_pairs(
instances, self._prev_instances, iou_all, threshold=self._track_iou_threshold
)
# assign large cost value to make sure pair below IoU threshold won't be matched
cost_matrix = np.full((len(instances), len(prev_instances)), LARGE_COST_VALUE)
return self.assign_cost_matrix_values(cost_matrix, bbox_pairs)
def assign_cost_matrix_values(self, cost_matrix: np.ndarray, bbox_pairs: List) -> np.ndarray:
"""
Based on IoU for each pair of bbox, assign the associated value in cost matrix
Args:
cost_matrix: np.ndarray, initialized 2D array with target dimensions
bbox_pairs: list of bbox pair, in each pair, iou value is stored
Return:
np.ndarray, cost_matrix with assigned values
"""
for pair in bbox_pairs:
# assign -1 for IoU above threshold pairs, algorithms will minimize cost
cost_matrix[pair["idx"]][pair["prev_idx"]] = -1
return cost_matrix
|