Files
aleju--imgaug/checks/check_readme_examples.py
2026-07-13 12:46:08 +08:00

513 lines
19 KiB
Python

"""
Script to verify all examples in the readme.
Simply execute
python test_readme_examples.py
The tests in this file are currently not unittests!
They do plot images.
TODO move this to checks/ ?
"""
from __future__ import print_function, division
import functools
def main():
example_simple_training_setting()
example_very_complex_augmentation_pipeline()
example_augment_images_and_keypoints()
example_augment_images_and_bounding_boxes()
example_augment_images_and_polygons()
example_augment_images_and_linestrings()
example_augment_images_and_heatmaps()
example_augment_images_and_segmentation_maps()
example_visualize_augmented_images()
example_visualize_augmented_non_image_data()
example_using_augmenters_only_once()
example_multicore_augmentation()
example_probability_distributions_as_parameters()
example_withchannels()
example_hooks()
def seeded(func):
@functools.wraps(func)
def wrapper(*args, **kwargs):
import imgaug.random as iarandom
iarandom.seed(0)
func(*args, **kwargs)
return wrapper
@seeded
def example_simple_training_setting():
print("Example: Simple Training Setting")
import numpy as np
import imgaug.augmenters as iaa
def load_batch(batch_idx):
# dummy function, implement this
# Return a numpy array of shape (N, height, width, #channels)
# or a list of (height, width, #channels) arrays (may have different image
# sizes).
# Images should be in RGB for colorspace augmentations.
# (cv2.imread() returns BGR!)
# Images should usually be in uint8 with values from 0-255.
return np.zeros((128, 32, 32, 3), dtype=np.uint8) + (batch_idx % 255)
def train_on_images(images):
# dummy function, implement this
pass
# Pipeline:
# (1) Crop images from each side by 1-16px, do not resize the results
# images back to the input size. Keep them at the cropped size.
# (2) Horizontally flip 50% of the images.
# (3) Blur images using a gaussian kernel with sigma between 0.0 and 3.0.
seq = iaa.Sequential([
iaa.Crop(px=(1, 16), keep_size=False),
iaa.Fliplr(0.5),
iaa.GaussianBlur(sigma=(0, 3.0))
])
for batch_idx in range(100):
images = load_batch(batch_idx)
images_aug = seq(images=images) # done by the library
train_on_images(images_aug)
# -----
# Make sure that the example really does something
if batch_idx == 0:
assert not np.array_equal(images, images_aug)
@seeded
def example_very_complex_augmentation_pipeline():
print("Example: Very Complex Augmentation Pipeline")
import numpy as np
import imgaug as ia
import imgaug.augmenters as iaa
# random example images
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
# Sometimes(0.5, ...) applies the given augmenter in 50% of all cases,
# e.g. Sometimes(0.5, GaussianBlur(0.3)) would blur roughly every second image.
sometimes = lambda aug: iaa.Sometimes(0.5, aug)
# Define our sequence of augmentation steps that will be applied to every image
# All augmenters with per_channel=0.5 will sample one value _per image_
# in 50% of all cases. In all other cases they will sample new values
# _per channel_.
seq = iaa.Sequential(
[
# apply the following augmenters to most images
iaa.Fliplr(0.5), # horizontally flip 50% of all images
iaa.Flipud(0.2), # vertically flip 20% of all images
# crop images by -5% to 10% of their height/width
sometimes(iaa.CropAndPad(
percent=(-0.05, 0.1),
pad_mode=ia.ALL,
pad_cval=(0, 255)
)),
sometimes(iaa.Affine(
scale={"x": (0.8, 1.2), "y": (0.8, 1.2)}, # scale images to 80-120% of their size, individually per axis
translate_percent={"x": (-0.2, 0.2), "y": (-0.2, 0.2)}, # translate by -20 to +20 percent (per axis)
rotate=(-45, 45), # rotate by -45 to +45 degrees
shear=(-16, 16), # shear by -16 to +16 degrees
order=[0, 1], # use nearest neighbour or bilinear interpolation (fast)
cval=(0, 255), # if mode is constant, use a cval between 0 and 255
mode=ia.ALL # use any of scikit-image's warping modes (see 2nd image from the top for examples)
)),
# execute 0 to 5 of the following (less important) augmenters per image
# don't execute all of them, as that would often be way too strong
iaa.SomeOf((0, 5),
[
sometimes(iaa.Superpixels(p_replace=(0, 1.0), n_segments=(20, 200))), # convert images into their superpixel representation
iaa.OneOf([
iaa.GaussianBlur((0, 3.0)), # blur images with a sigma between 0 and 3.0
iaa.AverageBlur(k=(2, 7)), # blur image using local means with kernel sizes between 2 and 7
iaa.MedianBlur(k=(3, 11)), # blur image using local medians with kernel sizes between 2 and 7
]),
iaa.Sharpen(alpha=(0, 1.0), lightness=(0.75, 1.5)), # sharpen images
iaa.Emboss(alpha=(0, 1.0), strength=(0, 2.0)), # emboss images
# search either for all edges or for directed edges,
# blend the result with the original image using a blobby mask
iaa.SimplexNoiseAlpha(iaa.OneOf([
iaa.EdgeDetect(alpha=(0.5, 1.0)),
iaa.DirectedEdgeDetect(alpha=(0.5, 1.0), direction=(0.0, 1.0)),
])),
iaa.AdditiveGaussianNoise(loc=0, scale=(0.0, 0.05*255), per_channel=0.5), # add gaussian noise to images
iaa.OneOf([
iaa.Dropout((0.01, 0.1), per_channel=0.5), # randomly remove up to 10% of the pixels
iaa.CoarseDropout((0.03, 0.15), size_percent=(0.02, 0.05), per_channel=0.2),
]),
iaa.Invert(0.05, per_channel=True), # invert color channels
iaa.Add((-10, 10), per_channel=0.5), # change brightness of images (by -10 to 10 of original value)
iaa.AddToHueAndSaturation((-20, 20)), # change hue and saturation
# either change the brightness of the whole image (sometimes
# per channel) or change the brightness of subareas
iaa.OneOf([
iaa.Multiply((0.5, 1.5), per_channel=0.5),
iaa.FrequencyNoiseAlpha(
exponent=(-4, 0),
first=iaa.Multiply((0.5, 1.5), per_channel=True),
second=iaa.LinearContrast((0.5, 2.0))
)
]),
iaa.LinearContrast((0.5, 2.0), per_channel=0.5), # improve or worsen the contrast
iaa.Grayscale(alpha=(0.0, 1.0)),
sometimes(iaa.ElasticTransformation(alpha=(0.5, 3.5), sigma=0.25)), # move pixels locally around (with random strengths)
sometimes(iaa.PiecewiseAffine(scale=(0.01, 0.05))), # sometimes move parts of the image around
sometimes(iaa.PerspectiveTransform(scale=(0.01, 0.1)))
],
random_order=True
)
],
random_order=True
)
images_aug = seq(images=images)
# -----
# Make sure that the example really does something
assert not np.array_equal(images, images_aug)
@seeded
def example_augment_images_and_keypoints():
print("Example: Augment Images and Keypoints")
import numpy as np
import imgaug.augmenters as iaa
images = np.zeros((2, 128, 128, 3), dtype=np.uint8) # two example images
images[:, 64, 64, :] = 255
points = [
[(10.5, 20.5)], # points on first image
[(50.5, 50.5), (60.5, 60.5), (70.5, 70.5)] # points on second image
]
seq = iaa.Sequential([
iaa.AdditiveGaussianNoise(scale=0.05*255),
iaa.Affine(translate_px={"x": (1, 5)})
])
# augment keypoints and images
images_aug, points_aug = seq(images=images, keypoints=points)
print("Image 1 center", np.argmax(images_aug[0, 64, 64:64+6, 0]))
print("Image 2 center", np.argmax(images_aug[1, 64, 64:64+6, 0]))
print("Points 1", points_aug[0])
print("Points 2", points_aug[1])
@seeded
def example_augment_images_and_bounding_boxes():
print("Example: Augment Images and Bounding Boxes")
import numpy as np
import imgaug as ia
import imgaug.augmenters as iaa
images = np.zeros((2, 128, 128, 3), dtype=np.uint8) # two example images
images[:, 64, 64, :] = 255
bbs = [
[ia.BoundingBox(x1=10.5, y1=15.5, x2=30.5, y2=50.5)],
[ia.BoundingBox(x1=10.5, y1=20.5, x2=50.5, y2=50.5),
ia.BoundingBox(x1=40.5, y1=75.5, x2=70.5, y2=100.5)]
]
seq = iaa.Sequential([
iaa.AdditiveGaussianNoise(scale=0.05*255),
iaa.Affine(translate_px={"x": (1, 5)})
])
images_aug, bbs_aug = seq(images=images, bounding_boxes=bbs)
@seeded
def example_augment_images_and_polygons():
print("Example: Augment Images and Polygons")
import numpy as np
import imgaug as ia
import imgaug.augmenters as iaa
images = np.zeros((2, 128, 128, 3), dtype=np.uint8) # two example images
images[:, 64, 64, :] = 255
polygons = [
[ia.Polygon([(10.5, 10.5), (50.5, 10.5), (50.5, 50.5)])],
[ia.Polygon([(0.0, 64.5), (64.5, 0.0), (128.0, 128.0), (64.5, 128.0)])]
]
seq = iaa.Sequential([
iaa.AdditiveGaussianNoise(scale=0.05*255),
iaa.Affine(translate_px={"x": (1, 5)})
])
images_aug, polygons_aug = seq(images=images, polygons=polygons)
@seeded
def example_augment_images_and_linestrings():
print("Example: Augment Images and LineStrings")
import numpy as np
import imgaug as ia
import imgaug.augmenters as iaa
images = np.zeros((2, 128, 128, 3), dtype=np.uint8) # two example images
images[:, 64, 64, :] = 255
ls = [
[ia.LineString([(10.5, 10.5), (50.5, 10.5), (50.5, 50.5)])],
[ia.LineString([(0.0, 64.5), (64.5, 0.0), (128.0, 128.0), (64.5, 128.0),
(128.0, 0.0)])]
]
seq = iaa.Sequential([
iaa.AdditiveGaussianNoise(scale=0.05*255),
iaa.Affine(translate_px={"x": (1, 5)})
])
images_aug, ls_aug = seq(images=images, line_strings=ls)
@seeded
def example_augment_images_and_heatmaps():
print("Example: Augment Images and Heatmaps")
import numpy as np
import imgaug.augmenters as iaa
# Standard scenario: You have N RGB-images and additionally 21 heatmaps per
# image. You want to augment each image and its heatmaps identically.
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
heatmaps = np.random.random(size=(16, 64, 64, 1)).astype(np.float32)
seq = iaa.Sequential([
iaa.GaussianBlur((0, 3.0)),
iaa.Affine(translate_px={"x": (-40, 40)}),
iaa.Crop(px=(0, 10))
])
images_aug, heatmaps_aug = seq(images=images, heatmaps=heatmaps)
@seeded
def example_augment_images_and_segmentation_maps():
print("Example: Augment Images and Segmentation Maps")
import numpy as np
import imgaug.augmenters as iaa
# Standard scenario: You have N=16 RGB-images and additionally one segmentation
# map per image. You want to augment each image and its heatmaps identically.
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
segmaps = np.random.randint(0, 10, size=(16, 64, 64, 1), dtype=np.int32)
seq = iaa.Sequential([
iaa.GaussianBlur((0, 3.0)),
iaa.Affine(translate_px={"x": (-40, 40)}),
iaa.Crop(px=(0, 10))
])
images_aug, segmaps_aug = seq(images=images, segmentation_maps=segmaps)
@seeded
def example_visualize_augmented_images():
print("Example: Visualize Augmented Images")
import numpy as np
import imgaug.augmenters as iaa
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
seq = iaa.Sequential([iaa.Fliplr(0.5), iaa.GaussianBlur((0, 3.0))])
# Show an image with 8*8 augmented versions of image 0 and 8*8 augmented
# versions of image 1. Identical augmentations will be applied to
# image 0 and 1.
seq.show_grid([images[0], images[1]], cols=8, rows=8)
@seeded
def example_visualize_augmented_non_image_data():
print("Example: Visualize Augmented Non-Image Data")
import numpy as np
import imgaug as ia
image = np.zeros((64, 64, 3), dtype=np.uint8)
# points
kps = [ia.Keypoint(x=10.5, y=20.5), ia.Keypoint(x=60.5, y=60.5)]
kpsoi = ia.KeypointsOnImage(kps, shape=image.shape)
image_with_kps = kpsoi.draw_on_image(image, size=7, color=(0, 0, 255))
ia.imshow(image_with_kps)
# bbs
bbsoi = ia.BoundingBoxesOnImage([
ia.BoundingBox(x1=10.5, y1=20.5, x2=50.5, y2=30.5)
], shape=image.shape)
image_with_bbs = bbsoi.draw_on_image(image)
image_with_bbs = ia.BoundingBox(
x1=50.5, y1=10.5, x2=100.5, y2=16.5
).draw_on_image(image_with_bbs, color=(255, 0, 0), size=3)
ia.imshow(image_with_bbs)
# polygons
psoi = ia.PolygonsOnImage([
ia.Polygon([(10.5, 20.5), (50.5, 30.5), (10.5, 50.5)])
], shape=image.shape)
image_with_polys = psoi.draw_on_image(
image, alpha_points=0, alpha_face=0.5, color_lines=(255, 0, 0))
ia.imshow(image_with_polys)
# heatmaps
# pick first result via [0] here, because one image per heatmap channel
# is generated
hms = ia.HeatmapsOnImage(np.random.random(size=(32, 32, 1)).astype(np.float32),
shape=image.shape)
image_with_hms = hms.draw_on_image(image)[0]
ia.imshow(image_with_hms)
@seeded
def example_using_augmenters_only_once():
print("Example: Using Augmenters Only Once")
from imgaug import augmenters as iaa
import numpy as np
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
# always horizontally flip each input image
images_aug = iaa.Fliplr(1.0)(images=images)
# vertically flip each input image with 90% probability
images_aug = iaa.Flipud(0.9)(images=images)
# blur 50% of all images using a gaussian kernel with a sigma of 3.0
images_aug = iaa.Sometimes(0.5, iaa.GaussianBlur(3.0))(images=images)
@seeded
def example_multicore_augmentation():
print("Example: Multicore Augmentation")
import skimage.data
import imgaug as ia
import imgaug.augmenters as iaa
from imgaug.augmentables.batches import UnnormalizedBatch
# Number of batches and batch size for this example
nb_batches = 10
batch_size = 32
# Example augmentation sequence to run in the background
augseq = iaa.Sequential([
iaa.Fliplr(0.5),
iaa.CoarseDropout(p=0.1, size_percent=0.1)
])
# For simplicity, we use the same image here many times
astronaut = skimage.data.astronaut()
astronaut = ia.imresize_single_image(astronaut, (64, 64))
# Make batches out of the example image (here: 10 batches, each 32 times
# the example image)
batches = []
for _ in range(nb_batches):
batches.append(UnnormalizedBatch(images=[astronaut] * batch_size))
# Show the augmented images.
# Note that augment_batches() returns a generator.
for images_aug in augseq.augment_batches(batches, background=True):
ia.imshow(ia.draw_grid(images_aug.images_aug, cols=8))
@seeded
def example_probability_distributions_as_parameters():
print("Example: Probability Distributions as Parameters")
import numpy as np
from imgaug import augmenters as iaa
from imgaug import parameters as iap
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
# Blur by a value sigma which is sampled from a uniform distribution
# of range 10.1 <= x < 13.0.
# The convenience shortcut for this is: GaussianBlur((10.1, 13.0))
blurer = iaa.GaussianBlur(10 + iap.Uniform(0.1, 3.0))
images_aug = blurer(images=images)
# Blur by a value sigma which is sampled from a gaussian distribution
# N(1.0, 0.1), i.e. sample a value that is usually around 1.0.
# Clip the resulting value so that it never gets below 0.1 or above 3.0.
blurer = iaa.GaussianBlur(iap.Clip(iap.Normal(1.0, 0.1), 0.1, 3.0))
images_aug = blurer(images=images)
@seeded
def example_withchannels():
print("Example: WithChannels")
import numpy as np
import imgaug.augmenters as iaa
# fake RGB images
images = np.random.randint(0, 255, (16, 128, 128, 3), dtype=np.uint8)
# add a random value from the range (-30, 30) to the first two channels of
# input images (e.g. to the R and G channels)
aug = iaa.WithChannels(
channels=[0, 1],
children=iaa.Add((-30, 30))
)
images_aug = aug(images=images)
@seeded
def example_hooks():
print("Example: Hooks")
import numpy as np
import imgaug as ia
import imgaug.augmenters as iaa
# Images and heatmaps, just arrays filled with value 30.
# We define the heatmaps here as uint8 arrays as we are going to feed them
# through the pipeline similar to normal images. In that way, every
# augmenter is applied to them.
images = np.full((16, 128, 128, 3), 30, dtype=np.uint8)
heatmaps = np.full((16, 128, 128, 21), 30, dtype=np.uint8)
# add vertical lines to see the effect of flip
images[:, 16:128-16, 120:124, :] = 120
heatmaps[:, 16:128-16, 120:124, :] = 120
seq = iaa.Sequential([
iaa.Fliplr(0.5, name="Flipper"),
iaa.GaussianBlur((0, 3.0), name="GaussianBlur"),
iaa.Dropout(0.02, name="Dropout"),
iaa.AdditiveGaussianNoise(scale=0.01*255, name="MyLittleNoise"),
iaa.AdditiveGaussianNoise(loc=32, scale=0.0001*255, name="SomeOtherNoise"),
iaa.Affine(translate_px={"x": (-40, 40)}, name="Affine")
])
# change the activated augmenters for heatmaps,
# we only want to execute horizontal flip, affine transformation and one of
# the gaussian noises
def activator_heatmaps(images, augmenter, parents, default):
if augmenter.name in ["GaussianBlur", "Dropout", "MyLittleNoise"]:
return False
else:
# default value for all other augmenters
return default
hooks_heatmaps = ia.HooksImages(activator=activator_heatmaps)
# call to_deterministic() once per batch, NOT only once at the start
seq_det = seq.to_deterministic()
images_aug = seq_det(images=images)
heatmaps_aug = seq_det(images=heatmaps, hooks=hooks_heatmaps)
# -----------
ia.show_grid(images_aug)
ia.show_grid(heatmaps_aug[..., 0:3])
if __name__ == "__main__":
main()