""" Contains Batch classes for images """
import os
import warnings
from numbers import Number
import numpy as np
try:
import PIL
import PIL.ImageOps
import PIL.ImageChops
import PIL.ImageFilter
import PIL.ImageEnhance
except ImportError:
pass
from scipy.ndimage import gaussian_filter, map_coordinates
from .batch import Batch
from .decorators import action, apply_parallel, inbatch_parallel
from .dsindex import FilesIndex
class BaseImagesBatch(Batch):
""" Batch class for 2D images.
Note, that if any class method is wrapped with `@apply_parallel` decorator
than for inner calls (i.e. from other class methods) should be used version
of desired method with underscores. (For example, if there is a decorated
`method` than you need to call `_method_` from inside of `other_method`).
Same is applicable for all child classes of :class:`batch.Batch`.
"""
components = "images", "labels", "masks"
# Class-specific defaults for :meth:`.Batch.apply_parallel`
apply_defaults = dict(target='for',
post='_assemble',
src='images',
dst='images',
)
def _make_path(self, ix, src=None):
""" Compose path.
Parameters
----------
ix : str
element's index (filename)
src : str
Path to folder with images. Used if `self.index` is not `FilesIndex`.
Returns
-------
path : str
Full path to an element.
"""
if isinstance(src, FilesIndex):
path = src.get_fullpath(ix)
elif isinstance(self.index, FilesIndex):
path = self.index.get_fullpath(ix)
else:
path = os.path.join(src, str(ix))
return path
def _load_image(self, ix, src=None, fmt=None, dst="images"):
""" Loads image.
.. note:: Please note that ``dst`` must be ``str`` only, sequence is not allowed here.
Parameters
----------
src : str, dataset.FilesIndex, None
path to the folder with an image. If src is None then it is determined from the index.
dst : str
Component to write images to.
fmt : str
Format of the an image
Raises
------
NotImplementedError
If this method is not defined in a child class
"""
_ = self, ix, src, dst, fmt
raise NotImplementedError("Must be implemented in a child class")
@action
def load(self, *args, src=None, fmt=None, dst=None, **kwargs):
""" Load data.
.. note:: if `fmt='images'` than ``components`` must be a single component (str).
.. note:: All parameters must be named only.
Parameters
----------
src : str, None
Path to the folder with data. If src is None then path is determined from the index.
fmt : {'image', 'blosc', 'csv', 'hdf5', 'feather'}
Format of the file to download.
dst : str, sequence
components to download.
"""
if fmt == 'image':
return self._load_image(src, fmt=fmt, dst=dst)
return super().load(src=src, fmt=fmt, dst=dst, *args, **kwargs)
def _dump_image(self, ix, src='images', dst=None, fmt=None):
""" Saves image to dst.
.. note:: Please note that ``src`` must be ``str`` only, sequence is not allowed here.
Parameters
----------
src : str
Component to get images from.
dst : str
Folder where to dump. If dst is None then it is determined from index.
Raises
------
NotImplementedError
If this method is not defined in a child class
"""
_ = self, ix, src, dst, fmt
raise NotImplementedError("Must be implemented in a child class")
@action
def dump(self, *args, dst=None, fmt=None, components="images", **kwargs):
""" Dump data.
.. note:: If `fmt='images'` than ``dst`` must be a single component (str).
.. note:: All parameters must be named only.
Parameters
----------
dst : str, None
Path to the folder where to dump. If dst is None then path is determined from the index.
fmt : {'image', 'blosc', 'csv', 'hdf5', 'feather'}
Format of the file to save.
components : str, sequence
Components to save.
ext: str
Format to save images to.
Returns
-------
self
"""
if fmt == 'image':
return self._dump_image(components, dst, fmt=kwargs.pop('ext'))
return super().dump(dst=dst, fmt=fmt, components=components, *args, **kwargs)
[docs]
class ImagesBatch(BaseImagesBatch):
""" Batch class for 2D images.
Images are stored as numpy arrays of PIL.Image.
PIL.Image has the following system of coordinates::
X
0 -------------- >
|
|
| images's pixels
|
|
Y v
Pixel's position is defined as (x, y)
Note, that if any class method is wrapped with `@apply_parallel` decorator
than for inner calls (i.e. from other class methods) should be used version
of desired method with underscores. (For example, if there is a decorated
`method` than you need to call `_method_` from inside of `other_method`).
Same is applicable for all child classes of :class:`batch.Batch`.
"""
@classmethod
def _get_image_shape(cls, image):
if isinstance(image, PIL.Image.Image):
return image.size
return image.shape[:2]
@property
def image_shape(self):
""": tuple - shape of the image"""
_, shapes_count = np.unique([image.size for image in self.images], return_counts=True, axis=0)
if len(shapes_count) == 1:
if isinstance(self.images[0], PIL.Image.Image):
return (*self.images[0].size, len(self.images[0].getbands()))
return self.images[0].shape
raise RuntimeError('Images have different shapes')
@inbatch_parallel(init='indices', post='_assemble')
def _load_image(self, ix, src=None, fmt=None, dst="images"):
""" Loads image
.. note:: Please note that ``dst`` must be ``str`` only, sequence is not allowed here.
Parameters
----------
src : str, dataset.FilesIndex, None
Path to the folder with an image. If src is None then it is determined from the index.
dst : str
Component to write images to.
fmt : str
Format of an image.
"""
return PIL.Image.open(self._make_path(ix, src))
@inbatch_parallel(init='indices')
def _dump_image(self, ix, src='images', dst=None, fmt=None):
""" Saves image to dst.
.. note:: Please note that ``src`` must be ``str`` only, sequence is not allowed here.
Parameters
----------
src : str
Component to get images from.
dst : str
Folder where to dump.
fmt : str
Format of saved image.
"""
if dst is None:
raise RuntimeError('You must specify `dst`')
image = self.get(ix, src)
ix = str(ix) + '.' + fmt if fmt is not None else str(ix)
image.save(os.path.join(dst, ix))
def _assemble_component(self, result, *args, component='images', **kwargs):
""" Assemble one component after parallel execution.
Parameters
----------
result : sequence, array_like
Results after inbatch_parallel.
component : str
component to assemble
"""
_ = args, kwargs
if isinstance(result[0], PIL.Image.Image):
setattr(self, component, np.asarray(result, dtype=object))
else:
try:
setattr(self, component, np.stack(result))
except ValueError:
array_result = np.empty(len(result), dtype=object)
array_result[:] = result
setattr(self, component, array_result)
[docs]
@apply_parallel
def to_pil(self, image, mode=None):
"""converts images in Batch to PIL format
Parameters
----------
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
"""
if isinstance(image, PIL.Image.Image):
return image
if mode is None:
if len(image.shape) == 2:
mode = 'L'
elif len(image.shape) == 3:
if image.shape[-1] == 3:
mode = 'RGB'
elif image.shape[-1] == 1:
mode = 'L'
image = image[:, :, 0]
elif image.shape[-1] == 2:
mode = 'LA'
elif image.shape[-1] == 4:
mode = 'RGBA'
else:
raise ValueError('Unknown image type as image has', image.shape[-1], 'channels')
elif mode == 'L' and len(image.shape) == 3:
image = image[..., 0]
return PIL.Image.fromarray(image, mode)
[docs]
def _calc_origin(self, image_shape, origin, background_shape):
""" Calculate coordinate of the input image with respect to the background.
Parameters
----------
image_shape : sequence
shape of the input image.
origin : array_like, sequence, {'center', 'top_left', 'top_right', 'bottom_left', 'bottom_right', 'random'}
Position of the input image with respect to the background. Can be one of:
- 'center' - place the center of the input image on the center of the background and crop
the input image accordingly.
- 'top_left' - place the upper-left corner of the input image on the upper-left of the background
and crop the input image accordingly.
- 'top_right' - crop an image such that upper-right corners of
an image and the cropping box coincide
- 'bottom_left' - crop an image such that lower-left corners of
an image and the cropping box coincide
- 'bottom_right' - crop an image such that lower-right corners of
an image and the cropping box coincide
- 'random' - place the upper-left corner of the input image on the randomly sampled position
in the background. Position is sampled uniformly such that there is no need for cropping.
- other - sequence of ints or sequence of floats in [0, 1) interval;
place the upper-left corner of the input image on the given position in the background.
If `origin` is a sequence of floats in [0, 1), it defines a relative position of
the origin in a valid region of image.
background_shape : sequence
shape of the background image.
Returns
-------
sequence : calculated origin in the form (column, row)
"""
if isinstance(origin, str):
if origin == 'top_left':
origin = 0, 0
elif origin == 'top_right':
origin = (background_shape[0]-image_shape[0]+1, 0)
elif origin == 'bottom_left':
origin = (0, background_shape[1]-image_shape[1]+1)
elif origin == 'bottom_right':
origin = (background_shape[0]-image_shape[0]+1,
background_shape[1]-image_shape[1]+1)
elif origin == 'center':
origin = np.maximum(0, np.asarray(background_shape) - image_shape) // 2
elif origin == 'random':
origin = (np.random.randint(background_shape[0]-image_shape[0]+1),
np.random.randint(background_shape[1]-image_shape[1]+1))
else:
msg = "If string, origin should be one of ['center', 'top_left', 'top_right', "\
f"'bottom_left', 'bottom_right', 'random']. Got '{origin}'."
raise ValueError(msg)
elif all(0 <= elem < 1 for elem in origin):
region = ((background_shape[0]-image_shape[0]+1),
(background_shape[1]-image_shape[1]+1))
origin = np.asarray(origin) * region
elif not all(isinstance(elem, int) for elem in origin):
msg = "If not a string, origin should be either a sequence of ints or "\
f"sequence of floats in [0, 1) interval. Got {origin}"
raise ValueError(msg)
return np.asarray(origin, dtype=np.int64)
[docs]
@apply_parallel
def scale(self, image, factor, preserve_shape=False, origin='center', resample=0, src=None, dst=None):
""" Scale the content of each image in the batch.
Resulting shape is obtained as original_shape * factor.
Parameters
-----------
factor : float, sequence
resulting shape is obtained as original_shape * factor
- float - scale all axes with the given factor
- sequence (factor_1, factort_2, ...) - scale each axis with the given factor separately
preserve_shape : bool
whether to preserve the shape of the image after scaling
origin : array-like, {'center', 'top_left', 'top_right', 'bottom_left', 'bottom_right', 'random'}
Relevant only if `preserve_shape` is True.
If `scale` < 1, defines position of the scaled image with respect to the original one's shape.
If `scale` > 1, defines position of cropping box.
Can be one of:
- 'center' - place the center of the input image on the center of the background and crop
the input image accordingly.
- 'top_left' - place the upper-left corner of the input image on the upper-left of the background
and crop the input image accordingly.
- 'top_right' - crop an image such that upper-right corners of
an image and the cropping box coincide
- 'bottom_left' - crop an image such that lower-left corners of
an image and the cropping box coincide
- 'bottom_right' - crop an image such that lower-right corners of
an image and the cropping box coincide
- 'random' - place the upper-left corner of the input image on the randomly sampled position
in the background. Position is sampled uniformly such that there is no need for cropping.
- array_like - sequence of ints or sequence of floats in [0, 1) interval;
place the upper-left corner of the input image on the given position in the background.
If `origin` is a sequence of floats in [0, 1), it defines a relative position
of the origin in a valid region of image.
resample: int
Parameter passed to PIL.Image.resize. Interpolation order
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
Notes
-----
Using 'random' option for origin with `src` as list with multiple elements will not result in same crop for each
element, as origin will be sampled independently for each `src` element.
To randomly sample same origin for a number of components, use `R` named expression for `origin` argument.
Returns
-------
self
"""
_ = src, dst
original_shape = self._get_image_shape(image)
rescaled_shape = list(np.int32(np.ceil(np.asarray(original_shape)*factor)))
rescaled_image = image.resize(rescaled_shape, resample=resample)
if preserve_shape:
rescaled_image = self._preserve_shape(original_shape, rescaled_image, origin)
return rescaled_image
[docs]
@apply_parallel
def crop(self, image, origin, shape, crop_boundaries=False, src=None, dst=None):
""" Crop an image.
Extract image data from the window of the size given by `shape` and placed at `origin`.
Parameters
----------
origin : sequence, str
Location of the cropping box. See :meth:`.ImagesBatch._calc_origin` for details.
shape : sequence
crop size in the form of (rows, columns)
crop_boundaries : bool
If `True` then crop is got only from image's area. Shape of the crop might diverge with the passed one
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
Notes
-----
Using 'random' origin with `src` as list with multiple elements will not result in same crop for each
element, as origin will be sampled independently for each `src` element.
To randomly sample same origin for a number of components, use `R` named expression for `origin` argument.
"""
_ = src, dst
origin = self._calc_origin(shape, origin, image.size)
right_bottom = origin + shape
if crop_boundaries:
out_of_boundaries = origin < 0
origin[out_of_boundaries] = 0
image_shape = np.asarray(image.size)
out_of_boundaries = right_bottom > image_shape
right_bottom[out_of_boundaries] = image_shape[out_of_boundaries]
return image.crop((*origin, *right_bottom))
[docs]
@apply_parallel
def put_on_background(self, image, background, origin, mask=None):
""" Put an image on a background at given origin
Parameters
----------
background : PIL.Image, np.ndarray of np.uint8
Blank background to put image on.
origin : sequence, str
Location of the cropping box. See :meth:`.ImagesBatch._calc_origin` for details.
mask : None, PIL.Image, np.ndarray of np.uint8
mask passed to PIL.Image.paste
Notes
-----
Using 'random' origin with `src` as list with multiple elements will not result in same crop for each
element, as origin will be sampled independently for each `src` element.
To randomly sample same origin for a number of components, use `R` named expression for `origin` argument.
"""
if not isinstance(background, PIL.Image.Image):
background = PIL.Image.fromarray(background)
else:
background = background.copy()
if not isinstance(mask, PIL.Image.Image):
mask = PIL.Image.fromarray(mask) if mask is not None else None
origin = list(self._calc_origin(self._get_image_shape(image), origin,
self._get_image_shape(background)))
background.paste(image, origin, mask)
return background
def _preserve_shape(self, original_shape, transformed_image, origin='center'):
""" Change the transformed image's shape by cropping and adding empty pixels to fit the shape of original image.
Parameters
----------
original_shape : sequence
transformed_image : np.ndarray
input_origin : array-like, {'center', 'top_left', 'random'}
Position of the scaled image with respect to the original one's shape.
- 'center' - place the center of the input image on the center of the background and crop
the input image accordingly.
- 'top_left' - place the upper-left corner of the input image on the upper-left of the background
and crop the input image accordingly.
- 'top_right' - crop an image such that upper-right corners of
an image and the cropping box coincide
- 'bottom_left' - crop an image such that lower-left corners of
an image and the cropping box coincide
- 'bottom_right' - crop an image such that lower-right corners of
an image and the cropping box coincide
- 'random' - place the upper-left corner of the input image on the randomly sampled position
in the background. Position is sampled uniformly such that there is no need for cropping.
- array_like - sequence of ints or sequence of floats in [0, 1) interval;
place the upper-left corner of the input image on the given position in the background.
If `origin` is a sequence of floats in [0, 1), it defines a relative position
of the origin in a valid region of image.
crop_origin: array-like, {'center', 'top_left', 'random'}
Position of crop from transformed image.
Has same values as `input_origin`.
Returns
-------
np.ndarray : image after described actions
"""
transformed_shape = self._get_image_shape(transformed_image)
if np.any(np.array(transformed_shape) < np.array(original_shape)):
n_channels = len(transformed_image.getbands())
if n_channels == 1:
background = np.zeros(original_shape, dtype=np.uint8)
else:
background = np.zeros((*original_shape, n_channels), dtype=np.uint8)
return self._put_on_background_(transformed_image, background, origin)
return self._crop_(transformed_image, origin, original_shape, True)
[docs]
@apply_parallel
def filter(self, image, mode, *args, **kwargs):
""" Filters an image. Calls ``image.filter(getattr(PIL.ImageFilter, mode)(*args, **kwargs))``.
For more details see `ImageFilter <http://pillow.readthedocs.io/en/stable/reference/ImageFilter.html>_`.
Parameters
----------
mode : str
Name of the filter.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
return image.filter(getattr(PIL.ImageFilter, mode)(*args, **kwargs))
[docs]
@apply_parallel
def resize(self, image, size, src=None, dst=None, *args, **kwargs):
""" Calls ``image.resize(*args, **kwargs)``.
For more details see `<https://pillow.readthedocs.io/en/stable/reference/Image.html#PIL.Image.Image.resize>_`.
Parameters
----------
size : tuple
the resulting size of the image. If one of the components of tuple is None,
corresponding dimension will be proportionally resized.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
_ = src, dst
if size[0] is None and size[1] is None:
raise ValueError('At least one component of the parameter "size" must be a number.')
if size[0] is None:
new_size = (int(image.size[0] * size[1] / image.size[1]), size[1])
elif size[1] is None:
new_size = (size[0], int(image.size[1] * size[0] / image.size[0]))
else:
new_size = size
return image.resize(new_size, *args, **kwargs)
[docs]
@apply_parallel
def shift(self, image, offset, mode='const', src=None, dst=None):
""" Shifts an image.
Parameters
----------
offset : (Number, Number)
mode : {'const', 'wrap'}
How to fill borders
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
_ = src, dst
if mode == 'const':
image = image.transform(size=image.size,
method=PIL.Image.AFFINE,
data=(1, 0, -offset[0], 0, 1, -offset[1]))
elif mode == 'wrap':
image = PIL.ImageChops.offset(image, *offset)
else:
raise ValueError("mode must be one of ['const', 'wrap']")
return image
[docs]
@apply_parallel
def pad(self, image, *args, **kwargs):
""" Calls ``PIL.ImageOps.expand``.
For more details see `<http://pillow.readthedocs.io/en/stable/reference/ImageOps.html#PIL.ImageOps.expand>`_.
Parameters
----------
offset : sequence
Size of the borders in pixels. The order is (left, top, right, bottom).
mode : {'const', 'wrap'}
Filling mode
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
return PIL.ImageOps.expand(image, *args, **kwargs)
[docs]
@apply_parallel
def rotate(self, image, *args, **kwargs):
""" Rotates an image.
kwargs are passed to PIL.Image.rotate
Parameters
----------
angle: Number
In degrees counter clockwise.
resample: int
Interpolation order
expand: bool
Whether to expand the output to hold the whole image. Default is False.
center: (Number, Number)
Center of rotation. Default is the center of the image.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
return image.rotate(*args, **kwargs)
[docs]
@apply_parallel
def flip(self, image, mode='lr', src=None, dst=None):
""" Flips image.
Parameters
----------
mode : {'lr', 'ud'}
- 'lr' - apply the left/right flip
- 'ud' - apply the upside/down flip
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
_ = src, dst
if mode == 'lr':
return PIL.ImageOps.mirror(image)
return PIL.ImageOps.flip(image)
[docs]
@apply_parallel
def invert(self, image, channels='all'):
""" Invert givn channels.
Parameters
----------
channels : int, sequence
Indices of the channels to invert.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
if channels == 'all':
image = PIL.ImageChops.invert(image)
else:
bands = list(image.split())
channels = (channels,) if isinstance(channels, Number) else channels
for channel in channels:
bands[channel] = PIL.ImageChops.invert(bands[channel])
image = PIL.Image.merge('RGB', bands)
return image
[docs]
@apply_parallel
def salt(self, image, p_noise=.015, color=255, size=(1, 1)):
""" Set random pixel on image to givan value.
Every pixel will be set to ``color`` value with probability ``p_noise``.
Parameters
----------
p_noise : float
Probability of salting a pixel.
color : float, int, sequence, callable
Color's value.
- int, float, sequence -- value of color
- callable -- color is sampled for every chosen pixel (rules are the same as for int, float and sequence)
size : int, sequence of int, callable
Size of salt
- int -- square salt with side ``size``
- sequence -- recangular salt in the form (row, columns)
- callable -- size is sampled for every chosen pixel (rules are the same as for int and sequence)
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
mask_size = np.asarray(self._get_image_shape(image))
mask_salt = np.random.binomial(1, p_noise, size=mask_size).astype(bool)
image = np.array(image)
if isinstance(size, (tuple, int)) and size in [1, (1, 1)] and not callable(color):
image[mask_salt] = color
else:
size_lambda = size if callable(size) else lambda: size
color_lambda = color if callable(color) else lambda: color
mask_salt = np.where(mask_salt)
for i in range(len(mask_salt[0])):
current_size = size_lambda()
current_size = (current_size, current_size) if isinstance(current_size, Number) else current_size
left_top = np.asarray((mask_salt[0][i], mask_salt[1][i]))
right_bottom = np.minimum(left_top + current_size, self._get_image_shape(image))
image[left_top[0]:right_bottom[0], left_top[1]:right_bottom[1]] = color_lambda()
return PIL.Image.fromarray(image)
[docs]
@apply_parallel
def clip(self, image, low=0, high=255):
""" Truncate image's pixels.
Parameters
----------
low : int, float, sequence
Actual pixel's value is equal max(value, low). If sequence is given, then its length must coincide
with the number of channels in an image and each channel is thresholded separately
high : int, float, sequence
Actual pixel's value is equal min(value, high). If sequence is given, then its length must coincide
with the number of channels in an image and each channel is thresholded separately
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
if isinstance(low, Number):
low = tuple([low]*3)
if isinstance(high, Number):
high = tuple([high]*3)
high = PIL.Image.new('RGB', image.size, high)
low = PIL.Image.new('RGB', image.size, low)
return PIL.ImageChops.lighter(PIL.ImageChops.darker(image, high), low)
[docs]
@apply_parallel
def enhance(self, image, layout='hcbs', factor=(1, 1, 1, 1)):
""" Apply enhancements from PIL.ImageEnhance to the image.
Parameters
----------
layout : str
defines layout of operations, default is `hcbs`:
h - color
c - contrast
b - brightness
s - sharpness
factor : float or tuple of float
factor of enhancement for each operation listed in `layout`.
"""
enhancements = {
'h': 'Color',
'c': 'Contrast',
'b': 'Brightness',
's': 'Sharpness'
}
if isinstance(factor, float):
factor = (factor,) * len(layout)
if len(layout) != len(factor):
raise ValueError("'layout' and 'factor' should be of same length!")
for alias, multiplier in zip(layout, factor):
enhancement = enhancements.get(alias)
if enhancement is None:
raise ValueError('Unknown enhancement alias: ', alias)
image = getattr(PIL.ImageEnhance, enhancement)(image).enhance(multiplier)
return image
[docs]
@apply_parallel
def multiply(self, image, multiplier=1., clip=False, preserve_type=False, src=None, dst=None):
""" Multiply each pixel by the given multiplier.
Parameters
----------
multiplier : float, sequence
clip : bool
whether to force image's pixels to be in [0, 255] or [0, 1.]
preserve_type : bool
Whether to preserve ``dtype`` of transformed images.
If ``False`` is given then the resulting type will be ``np.float``.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
_ = src, dst
multiplier = np.float32(multiplier)
if isinstance(image, PIL.Image.Image):
if preserve_type is False:
warnings.warn("Note that some info might be lost during `multiply` transformation since PIL.image "
"stores data as `np.uint8`. To suppress this warning, use `preserve_type=True` or "
"consider using `to_array` action before multiplication.")
return PIL.Image.fromarray(np.clip(multiplier*np.asarray(image), 0, 255).astype(np.uint8))
dtype = image.dtype if preserve_type else np.float32
if clip:
image = np.clip(multiplier*image, 0, 255 if dtype == np.uint8 else 1.)
else:
image = multiplier * image
return image.astype(dtype)
[docs]
@apply_parallel
def add(self, image, term=1., clip=False, preserve_type=False):
""" Add term to each pixel.
Parameters
----------
term : float, sequence
clip : bool
whether to force image's pixels to be in [0, 255] or [0, 1.]
preserve_type : bool
Whether to preserve ``dtype`` of transformed images.
If ``False`` is given then the resulting type will be ``np.float``.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
term = np.float32(term)
if isinstance(image, PIL.Image.Image):
return PIL.Image.fromarray(np.clip(term+np.asarray(image), 0, 255).astype(np.uint8))
dtype = image.dtype if preserve_type else np.float32
if clip:
image = np.clip(term+image, 0, 255 if dtype == np.uint8 else 1.)
else:
image = term + image
return image.astype(dtype)
[docs]
@apply_parallel
def pil_convert(self, image, mode="L"):
""" Convert image. Actually calls ``image.convert(mode)``.
Parameters
----------
mode : str
Pass 'L' to convert to grayscale
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
return image.convert(mode)
[docs]
@apply_parallel
def posterize(self, image, bits=4):
""" Posterizes image.
More concretely, it quantizes pixels' values so that they have``2^bits`` colors
Parameters
----------
bits : int
Number of bits used to store a color's component.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
return PIL.ImageOps.posterize(image, bits)
[docs]
@apply_parallel
def cutout(self, image, origin, shape, color):
""" Fills given areas with color
.. note:: It is assumed that ``origins``, ``shapes`` and ``colors`` have the same length.
Parameters
----------
origin : sequence, str
Location of the cropping box. See :meth:`.ImagesBatch._calc_origin` for details.
shape : sequence, int
Shape of a filled box. Can be one of:
- sequence - crop size in the form of (rows, columns)
- int - shape has squared form
color : sequence, number
Color of a filled box. Can be one of:
- sequence - (r,g,b) form
- number - grayscale
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
Notes
-----
Using 'random' origin with `src` as list with multiple elements will not result in same crop for each
element, as origin will be sampled independently for each `src` element.
To randomly sample same origin for a number of components, use `R` named expression for `origin` argument.
"""
image = image.copy()
shape = (shape, shape) if isinstance(shape, Number) else shape
origin = self._calc_origin(shape, origin, self._get_image_shape(image))
color = (color, color, color) if isinstance(color, Number) else color
image.paste(PIL.Image.new('RGB', tuple(shape), tuple(color)), tuple(origin))
return image
def _assemble_patches(self, patches, *args, dst, **kwargs):
""" Assembles patches after parallel execution.
Parameters
----------
patches : sequence
Patches to gather. pathces.shape must be like (batch.size, patches_i, patch_height, patch_width, n_channels)
dst : str
Component to put patches in.
"""
_ = args, kwargs
new_items = np.concatenate(patches)
setattr(self, dst, new_items)
return self
[docs]
@action
@inbatch_parallel(init='indices', post='_assemble_patches')
def split_to_patches(self, ix, patch_shape, stride=1, drop_last=False, src='images', dst=None):
""" Splits image to patches.
Small images with the same shape (``patch_shape``) are cropped from the original one with stride ``stride``.
Parameters
----------
patch_shape : int, sequence
Patch's shape in the from (rows, columns). If int is given then patches have square shape.
stride : int, square
Step of the moving window from which patches are cropped. If int is given then the window has square shape.
drop_last : bool
Whether to drop patches whose window covers area out of the image.
If False is passed then these patches are cropped from the edge of an image. See more in tutorials.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
_ = dst
image = self.get(ix, src)
image_shape = self._get_image_shape(image)
image = np.array(image)
stride = (stride, stride) if isinstance(stride, Number) else stride
patch_shape = (patch_shape, patch_shape) if isinstance(patch_shape, Number) else patch_shape
patches = []
def _iterate_columns(row_from, row_to):
column = 0
while column < image_shape[1]-patch_shape[1]+1:
patches.append(PIL.Image.fromarray(image[column:column+patch_shape[1], row_from:row_to]))
column += stride[1]
if not drop_last and column + patch_shape[1] != image_shape[1]:
patches.append(PIL.Image.fromarray(image[image_shape[1]-patch_shape[1]:image_shape[1],
row_from:row_to]))
row = 0
while row < image_shape[0]-patch_shape[0]+1:
_iterate_columns(row, row+patch_shape[0])
row += stride[0]
if not drop_last and row + patch_shape[0] != image_shape[0]:
_iterate_columns(image_shape[0]-patch_shape[0], image_shape[0])
array = np.empty(len(patches), dtype=object)
for i, patch in enumerate(patches):
array[i] = patch
return array
[docs]
@apply_parallel
def additive_noise(self, image, noise, clip=False, preserve_type=False):
""" Add additive noise to an image.
Parameters
----------
noise : callable
Distribution. Must have ``size`` parameter.
clip : bool
whether to force image's pixels to be in [0, 255] or [0, 1.]
preserve_type : bool
Whether to preserve ``dtype`` of transformed images.
If ``False`` is given then the resulting type will be ``np.float``.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
noise = noise(size=(*image.size, len(image.getbands())) if isinstance(image, PIL.Image.Image) else image.shape)
return self._add_(image, noise, clip, preserve_type)
[docs]
@apply_parallel
def multiplicative_noise(self, image, noise, clip=False, preserve_type=False):
""" Add multiplicative noise to an image.
Parameters
----------
noise : callable
Distribution. Must have ``size`` parameter.
clip : bool
whether to force image's pixels to be in [0, 255] or [0, 1.]
preserve_type : bool
Whether to preserve ``dtype`` of transformed images.
If ``False`` is given then the resulting type will be ``np.float``.
src : str
Component to get images from. Default is 'images'.
dst : str
Component to write images to. Default is 'images'.
p : float
Probability of applying the transform. Default is 1.
"""
noise = noise(size=(*image.size, len(image.getbands())) if isinstance(image, PIL.Image.Image) else image.shape)
return self._multiply_(image, noise, clip, preserve_type)