contrib.metrics.streaming_mean_iou
tf.contrib.metrics.streaming_mean_iou
tf.contrib.metrics.streaming_mean_iou
streaming_mean_iou( predictions, labels, num_classes, weights=None, metrics_collections=None, updates_collections=None, name=None )
Defined in tensorflow/contrib/metrics/python/ops/metric_ops.py
.
See the guide: Metrics (contrib) > Metric Ops
Calculate per-step mean Intersection-Over-Union (mIOU).
Mean Intersection-Over-Union is a common evaluation metric for semantic image segmentation, which first computes the IOU for each semantic class and then computes the average over classes. IOU is defined as follows: IOU = true_positive / (true_positive + false_positive + false_negative). The predictions are accumulated in a confusion matrix, weighted by weights
, and mIOU is then calculated from it.
For estimation of the metric over a stream of data, the function creates an update_op
operation that updates these variables and returns the mean_iou
.
If weights
is None
, weights default to 1. Use weights of 0 to mask values.
Args:
-
predictions
: ATensor
of prediction results for semantic labels, whose shape is [batch size] and typeint32
orint64
. The tensor will be flattened, if its rank > 1. -
labels
: ATensor
of ground truth labels with shape [batch size] and of typeint32
orint64
. The tensor will be flattened, if its rank > 1. -
num_classes
: The possible number of labels the prediction task can have. This value must be provided, since a confusion matrix of dimension = [num_classes, num_classes] will be allocated. -
weights
: An optionalTensor
whose shape is broadcastable topredictions
. -
metrics_collections
: An optional list of collections thatmean_iou
should be added to. -
updates_collections
: An optional list of collectionsupdate_op
should be added to. -
name
: An optional variable_scope name.
Returns:
-
mean_iou
: ATensor
representing the mean intersection-over-union. -
update_op
: An operation that increments the confusion matrix.
Raises:
-
ValueError
: Ifpredictions
andlabels
have mismatched shapes, or ifweights
is notNone
and its shape doesn't matchpredictions
, or if eithermetrics_collections
orupdates_collections
are not a list or tuple.
© 2017 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/api_docs/python/tf/contrib/metrics/streaming_mean_iou