tf.image.sample_distorted_bounding_box
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Generate a single randomly distorted bounding box for an image.
tf.image.sample_distorted_bounding_box(
image_size,
bounding_boxes,
seed=0,
min_object_covered=0.1,
aspect_ratio_range=None,
area_range=None,
max_attempts=None,
use_image_if_no_bounding_boxes=None,
name=None
)
Bounding box annotations are often supplied in addition to ground-truth labels
in image recognition or object localization tasks. A common technique for
training such a system is to randomly distort an image while preserving
its content, i.e. data augmentation. This Op outputs a randomly distorted
localization of an object, i.e. bounding box, given an image_size
,
bounding_boxes
and a series of constraints.
The output of this Op is a single bounding box that may be used to crop the
original image. The output is returned as 3 tensors: begin
, size
and
bboxes
. The first 2 tensors can be fed directly into tf.slice
to crop the
image. The latter may be supplied to tf.image.draw_bounding_boxes
to
visualize what the bounding box looks like.
Bounding boxes are supplied and returned as [y_min, x_min, y_max, x_max]
.
The bounding box coordinates are floats in [0.0, 1.0]
relative to the width
and the height of the underlying image.
For example,
# Generate a single distorted bounding box.
begin, size, bbox_for_draw = tf.image.sample_distorted_bounding_box(
tf.shape(image),
bounding_boxes=bounding_boxes,
min_object_covered=0.1)
# Draw the bounding box in an image summary.
image_with_box = tf.image.draw_bounding_boxes(tf.expand_dims(image, 0),
bbox_for_draw)
tf.compat.v1.summary.image('images_with_box', image_with_box)
# Employ the bounding box to distort the image.
distorted_image = tf.slice(image, begin, size)
Note that if no bounding box information is available, setting
use_image_if_no_bounding_boxes = true
will assume there is a single implicit
bounding box covering the whole image. If use_image_if_no_bounding_boxes
is
false and no bounding boxes are supplied, an error is raised.
For producing deterministic results given a seed
value, use
tf.image.stateless_sample_distorted_bounding_box
. Unlike using the seed
param with tf.image.random_*
ops, tf.image.stateless_random_*
ops
guarantee the same results given the same seed independent of how many times
the function is called, and independent of global seed settings
(e.g. tf.random.set_seed).
Args |
image_size
|
A Tensor . Must be one of the following types: uint8 , int8 ,
int16 , int32 , int64 . 1-D, containing [height, width, channels] .
|
bounding_boxes
|
A Tensor of type float32 . 3-D with shape [batch, N, 4]
describing the N bounding boxes associated with the image.
|
seed
|
An optional int . Defaults to 0 . If seed is set to non-zero, the
random number generator is seeded by the given seed . Otherwise, it is
seeded by a random seed.
|
min_object_covered
|
A Tensor of type float32 . Defaults to 0.1 . The
cropped area of the image must contain at least this fraction of any
bounding box supplied. The value of this parameter should be non-negative.
In the case of 0, the cropped area does not need to overlap any of the
bounding boxes supplied.
|
aspect_ratio_range
|
An optional list of floats . Defaults to [0.75,
1.33] . The cropped area of the image must have an aspect ratio = width /
height within this range.
|
area_range
|
An optional list of floats . Defaults to [0.05, 1] . The
cropped area of the image must contain a fraction of the supplied image
within this range.
|
max_attempts
|
An optional int . Defaults to 100 . Number of attempts at
generating a cropped region of the image of the specified constraints.
After max_attempts failures, return the entire image.
|
use_image_if_no_bounding_boxes
|
An optional bool . Defaults to False .
Controls behavior if no bounding boxes supplied. If true, assume an
implicit bounding box covering the whole input. If false, raise an error.
|
name
|
A name for the operation (optional).
|
Returns |
A tuple of Tensor objects (begin, size, bboxes).
|
begin
|
A Tensor . Has the same type as image_size . 1-D, containing
[offset_height, offset_width, 0] . Provide as input to
tf.slice .
|
size
|
A Tensor . Has the same type as image_size . 1-D, containing
[target_height, target_width, -1] . Provide as input to
tf.slice .
|
bboxes
|
A Tensor of type float32 . 3-D with shape [1, 1, 4] containing
the distorted bounding box.
Provide as input to tf.image.draw_bounding_boxes .
|
Raises |
ValueError
|
If no seed is specified and op determinism is enabled.
|
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Some content is licensed under the numpy license.
Last updated 2023-03-17 UTC.
[null,null,["Last updated 2023-03-17 UTC."],[],[],null,["# tf.image.sample_distorted_bounding_box\n\n\u003cbr /\u003e\n\n|-----------------------------------------------------------------------------------------------------------------------------------|\n| [View source on GitHub](https://github.com/tensorflow/tensorflow/blob/v2.9.3/tensorflow/python/ops/image_ops_impl.py#L3371-L3494) |\n\nGenerate a single randomly distorted bounding box for an image. \n\n tf.image.sample_distorted_bounding_box(\n image_size,\n bounding_boxes,\n seed=0,\n min_object_covered=0.1,\n aspect_ratio_range=None,\n area_range=None,\n max_attempts=None,\n use_image_if_no_bounding_boxes=None,\n name=None\n )\n\nBounding box annotations are often supplied in addition to ground-truth labels\nin image recognition or object localization tasks. A common technique for\ntraining such a system is to randomly distort an image while preserving\nits content, i.e. *data augmentation* . This Op outputs a randomly distorted\nlocalization of an object, i.e. bounding box, given an `image_size`,\n`bounding_boxes` and a series of constraints.\n\nThe output of this Op is a single bounding box that may be used to crop the\noriginal image. The output is returned as 3 tensors: `begin`, `size` and\n`bboxes`. The first 2 tensors can be fed directly into [`tf.slice`](../../tf/slice) to crop the\nimage. The latter may be supplied to [`tf.image.draw_bounding_boxes`](../../tf/image/draw_bounding_boxes) to\nvisualize what the bounding box looks like.\n\nBounding boxes are supplied and returned as `[y_min, x_min, y_max, x_max]`.\nThe bounding box coordinates are floats in `[0.0, 1.0]` relative to the width\nand the height of the underlying image.\n\nFor example, \n\n # Generate a single distorted bounding box.\n begin, size, bbox_for_draw = tf.image.sample_distorted_bounding_box(\n tf.shape(image),\n bounding_boxes=bounding_boxes,\n min_object_covered=0.1)\n\n # Draw the bounding box in an image summary.\n image_with_box = tf.image.draw_bounding_boxes(tf.expand_dims(image, 0),\n bbox_for_draw)\n tf.compat.v1.summary.image('images_with_box', image_with_box)\n\n # Employ the bounding box to distort the image.\n distorted_image = tf.slice(image, begin, size)\n\nNote that if no bounding box information is available, setting\n`use_image_if_no_bounding_boxes = true` will assume there is a single implicit\nbounding box covering the whole image. If `use_image_if_no_bounding_boxes` is\nfalse and no bounding boxes are supplied, an error is raised.\n\nFor producing deterministic results given a `seed` value, use\n[`tf.image.stateless_sample_distorted_bounding_box`](../../tf/image/stateless_sample_distorted_bounding_box). Unlike using the `seed`\nparam with `tf.image.random_*` ops, `tf.image.stateless_random_*` ops\nguarantee the same results given the same seed independent of how many times\nthe function is called, and independent of global seed settings\n(e.g. tf.random.set_seed).\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Args ---- ||\n|----------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `image_size` | A `Tensor`. Must be one of the following types: `uint8`, `int8`, `int16`, `int32`, `int64`. 1-D, containing `[height, width, channels]`. |\n| `bounding_boxes` | A `Tensor` of type `float32`. 3-D with shape `[batch, N, 4]` describing the N bounding boxes associated with the image. |\n| `seed` | An optional `int`. Defaults to `0`. If `seed` is set to non-zero, the random number generator is seeded by the given `seed`. Otherwise, it is seeded by a random seed. |\n| `min_object_covered` | A Tensor of type `float32`. Defaults to `0.1`. The cropped area of the image must contain at least this fraction of any bounding box supplied. The value of this parameter should be non-negative. In the case of 0, the cropped area does not need to overlap any of the bounding boxes supplied. |\n| `aspect_ratio_range` | An optional list of `floats`. Defaults to `[0.75, 1.33]`. The cropped area of the image must have an aspect `ratio = width / height` within this range. |\n| `area_range` | An optional list of `floats`. Defaults to `[0.05, 1]`. The cropped area of the image must contain a fraction of the supplied image within this range. |\n| `max_attempts` | An optional `int`. Defaults to `100`. Number of attempts at generating a cropped region of the image of the specified constraints. After `max_attempts` failures, return the entire image. |\n| `use_image_if_no_bounding_boxes` | An optional `bool`. Defaults to `False`. Controls behavior if no bounding boxes supplied. If true, assume an implicit bounding box covering the whole input. If false, raise an error. |\n| `name` | A name for the operation (optional). |\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Returns ------- ||\n|----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| A tuple of `Tensor` objects (begin, size, bboxes). ||\n| `begin` | A `Tensor`. Has the same type as `image_size`. 1-D, containing `[offset_height, offset_width, 0]`. Provide as input to [`tf.slice`](../../tf/slice). |\n| `size` | A `Tensor`. Has the same type as `image_size`. 1-D, containing `[target_height, target_width, -1]`. Provide as input to [`tf.slice`](../../tf/slice). |\n| `bboxes` | A `Tensor` of type `float32`. 3-D with shape `[1, 1, 4]` containing the distorted bounding box. Provide as input to [`tf.image.draw_bounding_boxes`](../../tf/image/draw_bounding_boxes). |\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Raises ------ ||\n|--------------|--------------------------------------------------------|\n| `ValueError` | If no seed is specified and op determinism is enabled. |\n\n\u003cbr /\u003e"]]