fiftyone.core.stages.MatchFrames

class documentation

class MatchFrames(ViewStage): (source)

Constructor: MatchFrames(filter, omit_empty)

Filters the frames in a video collection by the given filter.

Examples:

import fiftyone as fo
import fiftyone.zoo as foz
from fiftyone import ViewField as F

dataset = foz.load_zoo_dataset("quickstart-video")

#
# Match frames with at least 10 detections
#

num_objects = F("detections.detections").length()
stage = fo.MatchFrames(num_objects > 10)
view = dataset.add_stage(stage)

print(dataset.count())
print(view.count())

print(dataset.count("frames"))
print(view.count("frames"))

Parameters
filter	a `fiftyone.core.expressions.ViewExpression` or MongoDB aggregation expression that returns a boolean describing the filter to apply
omit_empty	whether to omit samples with no frame labels after filtering

Method	`__init__`	Undocumented
Method	`to_mongo`	Returns the MongoDB aggregation pipeline for the stage.
Method	`validate`	Validates that the stage can be applied to the given collection.
Property	`filter`	The filter expression.
Property	`omit_empty`	Whether to omit samples that have no frames after filtering.
Class Method	`_params`	Returns a list of JSON dicts describing the stage's supported parameters.
Method	`_get_mongo_expr`	Undocumented
Method	`_kwargs`	Returns a list of `[name, value]` lists describing the parameters of this stage instance.
Method	`_needs_frames`	Whether the stage requires frame labels of video samples to be attached.
Method	`_validate_params`	Undocumented
Instance Variable	`_filter`	Undocumented
Instance Variable	`_omit_empty`	Undocumented

Inherited from ViewStage:

Method	`__eq__`	Undocumented
Method	`__repr__`	Undocumented
Method	`__str__`	Undocumented
Method	`get_edited_fields`	Returns a list of names of fields or embedded fields that may have been edited by the stage, if any.
Method	`get_excluded_fields`	Returns a list of fields that have been excluded by the stage, if any.
Method	`get_filtered_fields`	Returns a list of names of fields or embedded fields that contain arrays have been filtered by the stage, if any.
Method	`get_group_expr`	Returns the dynamic group expression for the given stage, if any.
Method	`get_media_type`	Returns the media type outputted by this stage when applied to the given collection, if and only if it is different from the input type.
Method	`get_selected_fields`	Returns a list of fields that have been selected by the stage, if any.
Method	`load_view`	Loads the `fiftyone.core.view.DatasetView` containing the output of the stage.
Property	`has_view`	Whether this stage's output view should be loaded via `load_view` rather than appending stages to an aggregation pipeline via `to_mongo`.
Property	`outputs_dynamic_groups`	Whether this stage outputs or flattens dynamic groups.
Class Method	`_from_dict`	Creates a `ViewStage` instance from a serialized JSON dict representation of it.
Method	`_needs_group_slices`	Whether the stage requires group slice(s) to be attached.
Method	`_serialize`	Returns a JSON dict representation of the `ViewStage`.
Instance Variable	`_uuid`	Undocumented

def __init__(self, filter, omit_empty=True): (source) ¶

Undocumented

def to_mongo(self, _): (source) ¶

overrides fiftyone.core.stages.ViewStage.to_mongo

Returns the MongoDB aggregation pipeline for the stage.

Only usable if has_view is False.

Parameters
_	Undocumented
sample_collection	the `fiftyone.core.collections.SampleCollection` to which the stage is being applied
Returns
a MongoDB aggregation pipeline (list of dicts)

def validate(self, sample_collection): (source) ¶

overrides fiftyone.core.stages.ViewStage.validate

Validates that the stage can be applied to the given collection.

Parameters
sample_collection	a `fiftyone.core.collections.SampleCollection`
Raises
`ViewStageError`	if the stage cannot be applied to the collection

@property
filter = (source) ¶

The filter expression.

@property
omit_empty = (source) ¶

Whether to omit samples that have no frames after filtering.

@classmethod
def _params(cls): (source) ¶

overrides fiftyone.core.stages.ViewStage._params

Returns a list of JSON dicts describing the stage's supported parameters.

Returns
a list of JSON dicts

def _get_mongo_expr(self): (source) ¶

Undocumented

def _kwargs(self): (source) ¶

overrides fiftyone.core.stages.ViewStage._kwargs

Returns a list of [name, value] lists describing the parameters of this stage instance.

Returns
a list of `[name, value]` lists

def _needs_frames(self, _): (source) ¶

overrides fiftyone.core.stages.ViewStage._needs_frames

Whether the stage requires frame labels of video samples to be attached.

Parameters
_	Undocumented
sample_collection	the `fiftyone.core.collections.SampleCollection` to which the stage is being applied
Returns
True/False

def _validate_params(self): (source) ¶

Undocumented

_filter = (source) ¶

Undocumented

_omit_empty = (source) ¶

Undocumented