kwcoco.coco_objects1d

Vectorized ORM-like objects used in conjunction with coco_dataset

Module Contents

Classes

ObjectList1D	Vectorized access to lists of dictionary objects
ObjectGroups	An object for holding a groups of ObjectList1D objects
Categories	Vectorized access to category attributes
Videos	Vectorized access to video attributes
Images	Vectorized access to image attributes
Annots	Vectorized access to annotation attributes
AnnotGroups	An object for holding a groups of ObjectList1D objects
ImageGroups	An object for holding a groups of ObjectList1D objects

class kwcoco.coco_objects1d.ObjectList1D(ids, dset, key)

Bases: ubelt.NiceRepr

Vectorized access to lists of dictionary objects

Lightweight reference to a set of object (e.g. annotations, images) that allows for convenient property access.

Parameters

• ids (List[int]) – list of ids

• dset (CocoDataset) – parent dataset

• key (str) – main object name (e.g. ‘images’, ‘annotations’)

Types:

ObjT = Ann | Img | Cat # can be one of these types ObjectList1D gives us access to a List[ObjT]

Example

>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> # Both annots and images are object lists
>>> self = dset.annots()
>>> self = dset.images()
>>> # can call with a list of ids or not, for everything
>>> self = dset.annots([1, 2, 11])
>>> self = dset.images([1, 2, 3])
>>> self.lookup('id')
>>> self.lookup(['id'])

__nice__(self)

__iter__(self)

__len__(self)

property _id_to_obj(self)

__getitem__(self, index)

property objs(self)

Returns

all object dictionaries

Return type

List[ObjT]

take(self, idxs)

Take a subset by index

Returns

ObjectList1D

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().annots()
>>> assert len(self.take([0, 2, 3])) == 3

compress(self, flags)

Take a subset by flags

Returns

ObjectList1D

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().images()
>>> assert len(self.compress([True, False, True])) == 2

peek(self)

Return the first object dictionary

Returns

object dictionary

Return type

ObjT

Example

>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> self = dset.images()
>>> assert self.peek()['id'] == 1
>>> # Check that subsets return correct items
>>> sub0 = self.compress([i % 2 == 0 for i in range(len(self))])
>>> sub1 = self.compress([i % 2 == 1 for i in range(len(self))])
>>> assert sub0.peek()['id'] == 1
>>> assert sub1.peek()['id'] == 2

lookup(self, key, default=ub.NoParam, keepid=False)

Lookup a list of object attributes

Parameters

• key (str | Iterable) – name of the property you want to lookup can also be a list of names, in which case we return a dict

• default – if specified, uses this value if it doesn’t exist in an ObjT.

• keepid – if True, return a mapping from ids to the property

Returns

a list of whatever type the object is Dict[str, ObjT]

Return type

List[ObjT]

Example

>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> self = dset.annots()
>>> self.lookup('id')
>>> key = ['id']
>>> default = None
>>> self.lookup(key=['id', 'image_id'])
>>> self.lookup(key=['id', 'image_id'])
>>> self.lookup(key='foo', default=None, keepid=True)
>>> self.lookup(key=['foo'], default=None, keepid=True)
>>> self.lookup(key=['id', 'image_id'], keepid=True)

get(self, key, default=ub.NoParam, keepid=False)

Lookup a list of object attributes

Parameters

• key (str) – name of the property you want to lookup

• default – if specified, uses this value if it doesn’t exist in an ObjT.

• keepid – if True, return a mapping from ids to the property

Returns

a list of whatever type the object is Dict[str, ObjT]

Return type

List[ObjT]

Example

>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> self = dset.annots()
>>> self.get('id')
>>> self.get(key='foo', default=None, keepid=True)

_iter_get(self, key, default=ub.NoParam)

Iterator version of get, not in stable API yet.

set(self, key, values)

Assign a value to each annotation

Parameters

• key (str) – the annotation property to modify

• values (Iterable | scalar) – an iterable of values to set for each annot in the dataset. If the item is not iterable, it is assigned to all objects.

Example

>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> self = dset.annots()
>>> self.set('my-key1', 'my-scalar-value')
>>> self.set('my-key2', np.random.rand(len(self)))
>>> print('dset.imgs = {}'.format(ub.repr2(dset.imgs, nl=1)))
>>> self.get('my-key2')

_set(self, key, values)

faster less safe version of set

_lookup(self, key, default=ub.NoParam)

Example

>>> # xdoctest: +REQUIRES(--benchmark)
>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo('shapes256')
>>> self = annots = dset.annots()
>>> #
>>> import timerit
>>> ti = timerit.Timerit(100, bestof=10, verbose=2)
>>> #
>>> for timer in ti.reset('lookup'):
>>>     with timer:
>>>         self.lookup('image_id')
>>> #
>>> for timer in ti.reset('_lookup'):
>>>     with timer:
>>>         self._lookup('image_id')
>>> #
>>> for timer in ti.reset('image_id'):
>>>     with timer:
>>>         self.image_id
>>> #
>>> for timer in ti.reset('raw1'):
>>>     with timer:
>>>         key = 'image_id'
>>>         [self._dset.anns[_id][key] for _id in self._ids]
>>> #
>>> for timer in ti.reset('raw2'):
>>>     with timer:
>>>         anns = self._dset.anns
>>>         key = 'image_id'
>>>         [anns[_id][key] for _id in self._ids]
>>> #
>>> for timer in ti.reset('lut-gen'):
>>>     with timer:
>>>         _lut = self._obj_lut
>>>         objs = (_lut[_id] for _id in self._ids)
>>>         [obj[key] for obj in objs]
>>> #
>>> for timer in ti.reset('lut-gen-single'):
>>>     with timer:
>>>         _lut = self._obj_lut
>>>         [_lut[_id][key] for _id in self._ids]

attribute_frequency(self)

Compute the number of times each key is used in a dictionary

Returns

Dict[str, int]

Example

>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> self = dset.annots()
>>> attrs = self.attribute_frequency()
>>> print('attrs = {}'.format(ub.repr2(attrs, nl=1)))

class kwcoco.coco_objects1d.ObjectGroups(groups, dset)

Bases: ubelt.NiceRepr

An object for holding a groups of ObjectList1D objects

_lookup(self, key)

__getitem__(self, index)

lookup(self, key, default=ub.NoParam)

__nice__(self)

class kwcoco.coco_objects1d.Categories(ids, dset)

Bases: ObjectList1D

Vectorized access to category attributes

SeeAlso:

kwcoco.coco_dataset.MixinCocoObjects.categories()

Example

>>> from kwcoco.coco_objects1d import Categories  # NOQA
>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo()
>>> ids = list(dset.cats.keys())
>>> self = Categories(ids, dset)
>>> print('self.name = {!r}'.format(self.name))
>>> print('self.supercategory = {!r}'.format(self.supercategory))

property cids(self)

property name(self)

property supercategory(self)

class kwcoco.coco_objects1d.Videos(ids, dset)

Bases: ObjectList1D

Vectorized access to video attributes

SeeAlso:

kwcoco.coco_dataset.MixinCocoObjects.videos()

Example

>>> from kwcoco.coco_objects1d import Videos  # NOQA
>>> import kwcoco
>>> dset = kwcoco.CocoDataset.demo('vidshapes5')
>>> ids = list(dset.index.videos.keys())
>>> self = Videos(ids, dset)
>>> print('self = {!r}'.format(self))

property images(self)

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo('vidshapes8').videos()
>>> print(self.images)
<ImageGroups(n=8, m=2.0, s=0.0)>

class kwcoco.coco_objects1d.Images(ids, dset)

Bases: ObjectList1D

Vectorized access to image attributes

SeeAlso:

kwcoco.coco_dataset.MixinCocoObjects.images()

property coco_images(self)

property gids(self)

property gname(self)

property gpath(self)

property width(self)

property height(self)

property size(self)

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().images()
>>> self._dset._ensure_imgsize()
>>> print(self.size)
[(512, 512), (300, 250), (256, 256)]

property area(self)

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().images()
>>> self._dset._ensure_imgsize()
>>> print(self.area)
[262144, 75000, 65536]

property n_annots(self)

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().images()
>>> print(ub.repr2(self.n_annots, nl=0))
[9, 2, 0]

property aids(self)

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().images()
>>> print(ub.repr2(list(map(list, self.aids)), nl=0))
[[1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11], []]

property annots(self)

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().images()
>>> print(self.annots)
<AnnotGroups(n=3, m=3.7, s=3.9)>

class kwcoco.coco_objects1d.Annots(ids, dset)

Bases: ObjectList1D

Vectorized access to annotation attributes

SeeAlso:

kwcoco.coco_dataset.MixinCocoObjects.annots()

property aids(self)

The annotation ids of this column of annotations

property images(self)

Get the column of images

Returns

Images

property image_id(self)

property category_id(self)

property gids(self)

Get the column of image-ids

Returns

list of image ids

Return type

List[int]

property cids(self)

Get the column of category-ids

Returns

List[int]

property cnames(self)

Get the column of category names

Returns

List[int]

property detections(self)

Get the kwimage-style detection objects

Returns

kwimage.Detections

Example

>>> # xdoctest: +REQUIRES(module:kwimage)
>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo('shapes32').annots([1, 2, 11])
>>> dets = self.detections
>>> print('dets.data = {!r}'.format(dets.data))
>>> print('dets.meta = {!r}'.format(dets.meta))

property boxes(self)

Get the column of kwimage-style bounding boxes

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().annots([1, 2, 11])
>>> print(self.boxes)
<Boxes(xywh,
    array([[ 10,  10, 360, 490],
           [350,   5, 130, 290],
           [124,  96,  45,  18]]))>

property xywh(self)

Returns raw boxes

Example

>>> import kwcoco
>>> self = kwcoco.CocoDataset.demo().annots([1, 2, 11])
>>> print(self.xywh)

class kwcoco.coco_objects1d.AnnotGroups(groups, dset)

Bases: ObjectGroups

An object for holding a groups of ObjectList1D objects

property cids(self)

property cnames(self)

class kwcoco.coco_objects1d.ImageGroups(groups, dset)

Bases: ObjectGroups

An object for holding a groups of ObjectList1D objects