kwcoco.metrics.detect_metrics

Module Contents

Classes

DetectionMetrics

Object that computes associations between detections and can convert them

Functions

_demo_construct_probs(pred_cxs, pred_scores, classes, rng, hacked=1)	Constructs random probabilities for demo data
pycocotools_confusion_vectors(dmet, evaler, iou_thresh=0.5, verbose=0)	Example
eval_detections_cli(**kw)	DEPRECATED USE kwcoco eval instead
_summarize(self, ap=1, iouThr=None, areaRngLbl='all', maxDets=100)
pct_summarize2(self)

class kwcoco.metrics.detect_metrics.DetectionMetrics(dmet, classes=None)

Bases: ubelt.NiceRepr

Object that computes associations between detections and can convert them into sklearn-compatible representations for scoring.

Variables

• gid_to_true_dets (Dict) – maps image ids to truth

• gid_to_pred_dets (Dict) – maps image ids to predictions

• classes (CategoryTree) – category coder

Example

>>> dmet = DetectionMetrics.demo(
>>>     nimgs=100, nboxes=(0, 3), n_fp=(0, 1), classes=8, score_noise=0.9, hacked=False)
>>> print(dmet.score_kwcoco(bias=0, compat='mutex', prioritize='iou')['mAP'])
...
>>> # NOTE: IN GENERAL NETHARN AND VOC ARE NOT THE SAME
>>> print(dmet.score_voc(bias=0)['mAP'])
0.8582...
>>> #print(dmet.score_coco()['mAP'])

score_coco

clear(dmet)

__nice__(dmet)

classmethod from_coco(DetectionMetrics, true_coco, pred_coco, gids=None, verbose=0)

Create detection metrics from two coco files representing the truth and predictions.

Parameters

• true_coco (kwcoco.CocoDataset)

• pred_coco (kwcoco.CocoDataset)

Example

>>> import kwcoco
>>> from kwcoco.demo.perterb import perterb_coco
>>> true_coco = kwcoco.CocoDataset.demo('shapes')
>>> perterbkw = dict(box_noise=0.5, cls_noise=0.5, score_noise=0.5)
>>> pred_coco = perterb_coco(true_coco, **perterbkw)
>>> self = DetectionMetrics.from_coco(true_coco, pred_coco)
>>> self.score_voc()

_register_imagename(dmet, imgname, gid=None)

add_predictions(dmet, pred_dets, imgname=None, gid=None)

Register/Add predicted detections for an image

Parameters

• pred_dets (Detections) – predicted detections

• imgname (str) – a unique string to identify the image

• gid (int, optional) – the integer image id if known

add_truth(dmet, true_dets, imgname=None, gid=None)

Register/Add groundtruth detections for an image

Parameters

• true_dets (Detections) – groundtruth

• imgname (str) – a unique string to identify the image

• gid (int, optional) – the integer image id if known

true_detections(dmet, gid)

gets Detections representation for groundtruth in an image

pred_detections(dmet, gid)

gets Detections representation for predictions in an image

confusion_vectors(dmet, iou_thresh=0.5, bias=0, gids=None, compat='mutex', prioritize='iou', ignore_classes='ignore', background_class=ub.NoParam, verbose='auto', workers=0, track_probs='try', max_dets=None)

Assigns predicted boxes to the true boxes so we can transform the detection problem into a classification problem for scoring.

Parameters

• iou_thresh (float | List[float], default=0.5) – bounding box overlap iou threshold required for assignment if a list, then return type is a dict

• bias (float, default=0.0) – for computing bounding box overlap, either 1 or 0

• gids (List[int], default=None) – which subset of images ids to compute confusion metrics on. If not specified all images are used.

• compat (str, default=’all’) – can be (‘ancestors’ | ‘mutex’ | ‘all’). determines which pred boxes are allowed to match which true boxes. If ‘mutex’, then pred boxes can only match true boxes of the same class. If ‘ancestors’, then pred boxes can match true boxes that match or have a coarser label. If ‘all’, then any pred can match any true, regardless of its category label.

• prioritize (str, default=’iou’) – can be (‘iou’ | ‘class’ | ‘correct’) determines which box to assign to if mutiple true boxes overlap a predicted box. if prioritize is iou, then the true box with maximum iou (above iou_thresh) will be chosen. If prioritize is class, then it will prefer matching a compatible class above a higher iou. If prioritize is correct, then ancestors of the true class are preferred over descendents of the true class, over unreleated classes.

• ignore_classes (set, default={‘ignore’}) – class names indicating ignore regions

• background_class (str, default=ub.NoParam) – Name of the background class. If unspecified we try to determine it with heuristics. A value of None means there is no background class.

• verbose (int, default=’auto’) – verbosity flag. In auto mode, verbose=1 if len(gids) > 1000.

• workers (int, default=0) – number of parallel assignment processes

• track_probs (str, default=’try’) – can be ‘try’, ‘force’, or False. if truthy, we assume probabilities for multiple classes are available.

Returns

ConfusionVectors | Dict[float, ConfusionVectors]

Example

>>> dmet = DetectionMetrics.demo(nimgs=30, classes=3,
>>>                              nboxes=10, n_fp=3, box_noise=10,
>>>                              with_probs=False)
>>> iou_to_cfsn = dmet.confusion_vectors(iou_thresh=[0.3, 0.5, 0.9])
>>> for t, cfsn in iou_to_cfsn.items():
>>>     print('t = {!r}'.format(t))
...     print(cfsn.binarize_ovr().measures())
...     print(cfsn.binarize_classless().measures())

score_kwant(dmet, iou_thresh=0.5)

Scores the detections using kwant

score_kwcoco(dmet, iou_thresh=0.5, bias=0, gids=None, compat='all', prioritize='iou')

our scoring method

score_voc(dmet, iou_thresh=0.5, bias=1, method='voc2012', gids=None, ignore_classes='ignore')

score using voc method

Example

>>> dmet = DetectionMetrics.demo(
>>>     nimgs=100, nboxes=(0, 3), n_fp=(0, 1), classes=8,
>>>     score_noise=.5)
>>> print(dmet.score_voc()['mAP'])
0.9399...

_to_coco(dmet)

Convert to a coco representation of truth and predictions

with inverse aid mappings

score_pycocotools(dmet, with_evaler=False, with_confusion=False, verbose=0, iou_thresholds=None)

score using ms-coco method

Returns

dictionary with pct info

Return type

Dict

Example

>>> # xdoctest: +REQUIRES(module:pycocotools)
>>> from kwcoco.metrics.detect_metrics import *
>>> dmet = DetectionMetrics.demo(
>>>     nimgs=10, nboxes=(0, 3), n_fn=(0, 1), n_fp=(0, 1), classes=8, with_probs=False)
>>> pct_info = dmet.score_pycocotools(verbose=1,
>>>                                   with_evaler=True,
>>>                                   with_confusion=True,
>>>                                   iou_thresholds=[0.5, 0.9])
>>> evaler = pct_info['evaler']
>>> iou_to_cfsn_vecs = pct_info['iou_to_cfsn_vecs']
>>> for iou_thresh in iou_to_cfsn_vecs.keys():
>>>     print('iou_thresh = {!r}'.format(iou_thresh))
>>>     cfsn_vecs = iou_to_cfsn_vecs[iou_thresh]
>>>     ovr_measures = cfsn_vecs.binarize_ovr().measures()
>>>     print('ovr_measures = {}'.format(ub.repr2(ovr_measures, nl=1, precision=4)))

Note

by default pycocotools computes average precision as the literal average of computed precisions at 101 uniformly spaced recall thresholds.

pycocoutils seems to only allow predictions with the same category as the truth to match those truth objects. This should be the same as calling dmet.confusion_vectors with compat = mutex

pycocoutils does not take into account the fact that each box often has a score for each category.

pycocoutils will be incorrect if any annotation has an id of 0

a major difference in the way kwcoco scores versus pycocoutils is the calculation of AP. The assignment between truth and predicted detections produces similar enough results. Given our confusion vectors we use the scikit-learn definition of AP, whereas pycocoutils seems to compute precision and recall — more or less correctly — but then it resamples the precision at various specified recall thresholds (in the accumulate function, specifically how pr is resampled into the q array). This can lead to a large difference in reported scores.

pycocoutils also smooths out the precision such that it is monotonic decreasing, which might not be the best idea.

pycocotools area ranges are inclusive on both ends, that means the “small” and “medium” truth selections do overlap somewhat.

classmethod demo(cls, **kwargs)

Creates random true boxes and predicted boxes that have some noisy offset from the truth.

Kwargs:

classes (int, default=1): class list or the number of foreground

classes.

nimgs (int, default=1): number of images in the coco datasts. nboxes (int, default=1): boxes per image. n_fp (int, default=0): number of false positives. n_fn (int, default=0): number of false negatives. box_noise (float, default=0): std of a normal distribution used to

perterb both box location and box size.

cls_noise (float, default=0): probability that a class label will

change. Must be within 0 and 1.

anchors (ndarray, default=None): used to create random boxes null_pred (bool, default=0):

if True, predicted classes are returned as null, which means only localization scoring is suitable.

with_probs (bool, default=1):

if True, includes per-class probabilities with predictions

CommandLine

xdoctest -m kwcoco.metrics.detect_metrics DetectionMetrics.demo:2 --show

Example

>>> kwargs = {}
>>> # Seed the RNG
>>> kwargs['rng'] = 0
>>> # Size parameters determine how big the data is
>>> kwargs['nimgs'] = 5
>>> kwargs['nboxes'] = 7
>>> kwargs['classes'] = 11
>>> # Noise parameters perterb predictions further from the truth
>>> kwargs['n_fp'] = 3
>>> kwargs['box_noise'] = 0.1
>>> kwargs['cls_noise'] = 0.5
>>> dmet = DetectionMetrics.demo(**kwargs)
>>> print('dmet.classes = {}'.format(dmet.classes))
dmet.classes = <CategoryTree(nNodes=12, maxDepth=3, maxBreadth=4...)>
>>> # Can grab kwimage.Detection object for any image
>>> print(dmet.true_detections(gid=0))
<Detections(4)>
>>> print(dmet.pred_detections(gid=0))
<Detections(7)>

Example

>>> # Test case with null predicted categories
>>> dmet = DetectionMetrics.demo(nimgs=30, null_pred=1, classes=3,
>>>                              nboxes=10, n_fp=3, box_noise=0.1,
>>>                              with_probs=False)
>>> dmet.gid_to_pred_dets[0].data
>>> dmet.gid_to_true_dets[0].data
>>> cfsn_vecs = dmet.confusion_vectors()
>>> binvecs_ovr = cfsn_vecs.binarize_ovr()
>>> binvecs_per = cfsn_vecs.binarize_classless()
>>> measures_per = binvecs_per.measures()
>>> measures_ovr = binvecs_ovr.measures()
>>> print('measures_per = {!r}'.format(measures_per))
>>> print('measures_ovr = {!r}'.format(measures_ovr))
>>> # xdoctest: +REQUIRES(--show)
>>> import kwplot
>>> kwplot.autompl()
>>> measures_ovr['perclass'].draw(key='pr', fnum=2)

Example

>>> from kwcoco.metrics.confusion_vectors import *  # NOQA
>>> from kwcoco.metrics.detect_metrics import DetectionMetrics
>>> dmet = DetectionMetrics.demo(
>>>     n_fp=(0, 1), n_fn=(0, 1), nimgs=32, nboxes=(0, 16),
>>>     classes=3, rng=0, newstyle=1, box_noise=0.5, cls_noise=0.0, score_noise=0.3, with_probs=False)
>>> # xdoctest: +REQUIRES(--show)
>>> import kwplot
>>> kwplot.autompl()
>>> summary = dmet.summarize(plot=True, title='DetectionMetrics summary demo', with_ovr=True, with_bin=False)
>>> summary['bin_measures']
>>> kwplot.show_if_requested()

summarize(dmet, out_dpath=None, plot=False, title='', with_bin='auto', with_ovr='auto')

Example

>>> from kwcoco.metrics.confusion_vectors import *  # NOQA
>>> from kwcoco.metrics.detect_metrics import DetectionMetrics
>>> dmet = DetectionMetrics.demo(
>>>     n_fp=(0, 128), n_fn=(0, 4), nimgs=512, nboxes=(0, 32),
>>>     classes=3, rng=0)
>>> # xdoctest: +REQUIRES(--show)
>>> import kwplot
>>> kwplot.autompl()
>>> dmet.summarize(plot=True, title='DetectionMetrics summary demo')
>>> kwplot.show_if_requested()

kwcoco.metrics.detect_metrics._demo_construct_probs(pred_cxs, pred_scores, classes, rng, hacked=1)

Constructs random probabilities for demo data

kwcoco.metrics.detect_metrics.pycocotools_confusion_vectors(dmet, evaler, iou_thresh=0.5, verbose=0)

Example

>>> # xdoctest: +REQUIRES(module:pycocotools)
>>> from kwcoco.metrics.detect_metrics import *
>>> dmet = DetectionMetrics.demo(
>>>     nimgs=10, nboxes=(0, 3), n_fn=(0, 1), n_fp=(0, 1), classes=8, with_probs=False)
>>> coco_scores = dmet.score_pycocotools(with_evaler=True)
>>> evaler = coco_scores['evaler']
>>> cfsn_vecs = pycocotools_confusion_vectors(dmet, evaler, verbose=1)

kwcoco.metrics.detect_metrics.eval_detections_cli(**kw)

DEPRECATED USE kwcoco eval instead

CommandLine

xdoctest -m ~/code/kwcoco/kwcoco/metrics/detect_metrics.py eval_detections_cli

kwcoco.metrics.detect_metrics._summarize(self, ap=1, iouThr=None, areaRngLbl='all', maxDets=100)

kwcoco.metrics.detect_metrics.pct_summarize2(self)