"""
Image Input / Output Utilities
==============================
Defines the image related input / output utilities objects.
"""
from __future__ import annotations
import numpy as np
from dataclasses import dataclass, field
from colour.hints import (
Any,
ArrayLike,
Boolean,
DTypeNumber,
List,
Literal,
NDArray,
Optional,
Sequence,
Tuple,
Type,
Union,
cast,
)
from colour.utilities import (
CaseInsensitiveMapping,
as_float_array,
as_int_array,
attest,
is_openimageio_installed,
filter_kwargs,
optional,
required,
usage_warning,
validate_method,
)
__author__ = "Colour Developers"
__copyright__ = "Copyright 2013 Colour Developers"
__license__ = "New BSD License - https://opensource.org/licenses/BSD-3-Clause"
__maintainer__ = "Colour Developers"
__email__ = "colour-developers@colour-science.org"
__status__ = "Production"
__all__ = [
"BitDepth_Specification",
"ImageAttribute_Specification",
"convert_bit_depth",
"read_image_OpenImageIO",
"read_image_Imageio",
"READ_IMAGE_METHODS",
"read_image",
"write_image_OpenImageIO",
"write_image_Imageio",
"WRITE_IMAGE_METHODS",
"write_image",
]
@dataclass(frozen=True)
class BitDepth_Specification:
"""
Define a bit depth specification.
Parameters
----------
name
Attribute name.
numpy
Object representing the *Numpy* bit depth.
openimageio
Object representing the *OpenImageIO* bit depth.
"""
name: str
numpy: Type[DTypeNumber]
openimageio: Any
[docs]@dataclass
class ImageAttribute_Specification:
"""
Define an image specification attribute.
Parameters
----------
name
Attribute name.
value
Attribute value.
type_
Attribute type as an *OpenImageIO* :class:`TypeDesc` class instance.
"""
name: str
value: Any
type_: Optional[OpenImageIO.TypeDesc] = field( # type: ignore[name-defined] # noqa
default_factory=lambda: None
)
if is_openimageio_installed(): # pragma: no cover
from OpenImageIO import UINT8, UINT16, HALF, FLOAT, DOUBLE
MAPPING_BIT_DEPTH: CaseInsensitiveMapping = CaseInsensitiveMapping(
{
"uint8": BitDepth_Specification("uint8", np.uint8, UINT8),
"uint16": BitDepth_Specification("uint16", np.uint16, UINT16),
"float16": BitDepth_Specification("float16", np.float16, HALF),
"float32": BitDepth_Specification("float32", np.float32, FLOAT),
"float64": BitDepth_Specification("float64", np.float64, DOUBLE),
}
)
if hasattr(np, "float128"): # pragma: no cover
MAPPING_BIT_DEPTH["float128"] = BitDepth_Specification(
"float128", np.float128, DOUBLE # type: ignore[arg-type]
)
else: # pragma: no cover
MAPPING_BIT_DEPTH: CaseInsensitiveMapping = ( # type: ignore[no-redef]
CaseInsensitiveMapping(
{
"uint8": BitDepth_Specification("uint8", np.uint8, None),
"uint16": BitDepth_Specification("uint16", np.uint16, None),
"float16": BitDepth_Specification("float16", np.float16, None),
"float32": BitDepth_Specification("float32", np.float32, None),
"float64": BitDepth_Specification("float64", np.float64, None),
}
)
)
if hasattr(np, "float128"): # pragma: no cover
MAPPING_BIT_DEPTH["float128"] = BitDepth_Specification(
"float128", np.float128, None # type: ignore[arg-type]
)
[docs]def convert_bit_depth(
a: ArrayLike,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
) -> NDArray:
"""
Convert given array to given bit depth, the current bit depth of the array
is used to determine the appropriate conversion path.
Parameters
----------
a
Array to convert to given bit depth.
bit_depth
Bit depth.
Returns
-------
:class`numpy.ndarray`
Converted array.
Examples
--------
>>> a = np.array([0.0, 0.5, 1.0])
>>> convert_bit_depth(a, 'uint8')
array([ 0, 128, 255], dtype=uint8)
>>> convert_bit_depth(a, 'uint16')
array([ 0, 32768, 65535], dtype=uint16)
>>> convert_bit_depth(a, 'float16')
array([ 0. , 0.5, 1. ], dtype=float16)
>>> a = np.array([0, 128, 255], dtype=np.uint8)
>>> convert_bit_depth(a, 'uint16')
array([ 0, 32896, 65535], dtype=uint16)
>>> convert_bit_depth(a, 'float32') # doctest: +ELLIPSIS
array([ 0. , 0.501960..., 1. ], dtype=float32)
"""
a = np.asarray(a)
bit_depths = ", ".join(sorted(MAPPING_BIT_DEPTH.keys()))
attest(
bit_depth in bit_depths,
f'Incorrect bit depth was specified, it must be one of: "{bit_depths}"!',
)
attest(
str(a.dtype) in bit_depths,
f'Image bit depth must be one of: "{bit_depths}"!',
)
source_dtype = str(a.dtype)
target_dtype = MAPPING_BIT_DEPTH[bit_depth].numpy
if source_dtype == "uint8":
if bit_depth == "uint16":
a = (a * 257).astype(target_dtype)
elif bit_depth in ("float16", "float32", "float64", "float128"):
a = (a / 255).astype(target_dtype)
elif source_dtype == "uint16":
if bit_depth == "uint8":
a = (a / 257).astype(target_dtype)
elif bit_depth in ("float16", "float32", "float64", "float128"):
a = (a / 65535).astype(target_dtype)
elif source_dtype in ("float16", "float32", "float64", "float128"):
if bit_depth == "uint8":
a = np.around(a * 255).astype(target_dtype)
elif bit_depth == "uint16":
a = np.around(a * 65535).astype(target_dtype)
elif bit_depth in ("float16", "float32", "float64", "float128"):
a = a.astype(target_dtype)
return a # type: ignore[return-value]
[docs]@required("OpenImageIO")
def read_image_OpenImageIO(
path: str,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
attributes: Boolean = False,
) -> Union[NDArray, Tuple[NDArray, List]]: # noqa: D405,D410,D407,D411
"""
Read the image at given path using *OpenImageIO*.
Parameters
----------
path
Image path.
bit_depth
Returned image bit depth, the bit depth conversion behaviour is driven
directly by *OpenImageIO*, this definition only converts to the
relevant data type after reading.
attributes
Whether to return the image attributes.
Returns
-------
:class`numpy.ndarray` or :class:`tuple`
Image data or tuple of image data and list of
:class:`colour.io.ImageAttribute_Specification` class instances.
Notes
-----
- For convenience, single channel images are squeezed to 2D arrays.
Examples
--------
>>> import os
>>> import colour
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMS_Test_Pattern.exr')
>>> image = read_image_OpenImageIO(path) # doctest: +SKIP
"""
from OpenImageIO import ImageInput
path = str(path)
bit_depth_specification = MAPPING_BIT_DEPTH[bit_depth]
image = ImageInput.open(path)
specification = image.spec()
shape = (
specification.height,
specification.width,
specification.nchannels,
)
image_data = image.read_image(bit_depth_specification.openimageio)
image.close()
image = np.squeeze(
np.array(image_data, dtype=bit_depth_specification.numpy).reshape(
shape
)
)
if attributes:
extra_attributes = []
for i in range(len(specification.extra_attribs)):
attribute = specification.extra_attribs[i]
extra_attributes.append(
ImageAttribute_Specification(
attribute.name, attribute.value, attribute.type
)
)
return image, extra_attributes
else:
return image
[docs]def read_image_Imageio(
path: str,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
**kwargs: Any,
) -> NDArray:
"""
Read the image at given path using *Imageio*.
Parameters
----------
path
Image path.
bit_depth
Returned image bit depth, the image data is converted with
:func:`colour.io.convert_bit_depth` definition after reading the
image.
Other Parameters
----------------
kwargs
Keywords arguments.
Returns
-------
:class`numpy.ndarray`
Image data.
Notes
-----
- For convenience, single channel images are squeezed to 2D arrays.
Examples
--------
>>> import os
>>> import colour
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMS_Test_Pattern.exr')
>>> image = read_image_Imageio(path)
>>> image.shape # doctest: +SKIP
(1267, 1274, 3)
>>> image.dtype
dtype('float32')
"""
from imageio import imread
image = np.squeeze(imread(path, **kwargs))
return convert_bit_depth(image, bit_depth)
READ_IMAGE_METHODS: CaseInsensitiveMapping = CaseInsensitiveMapping(
{
"Imageio": read_image_Imageio,
"OpenImageIO": read_image_OpenImageIO,
}
)
READ_IMAGE_METHODS.__doc__ = """
Supported image read methods.
"""
[docs]def read_image(
path: str,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
method: Union[Literal["Imageio", "OpenImageIO"], str] = "OpenImageIO",
**kwargs: Any,
) -> NDArray: # noqa: D405,D407,D410,D411,D414
"""
Read the image at given path using given method.
Parameters
----------
path
Image path.
bit_depth
Returned image bit depth, for the *Imageio* method, the image data is
converted with :func:`colour.io.convert_bit_depth` definition after
reading the image, for the *OpenImageIO* method, the bit depth
conversion behaviour is driven directly by the library, this definition
only converts to the relevant data type after reading.
method
Read method, i.e. the image library used for reading images.
Other Parameters
----------------
attributes
{:func:`colour.io.read_image_OpenImageIO`},
Whether to return the image attributes.
Returns
-------
:class`numpy.ndarray`
Image data.
Notes
-----
- If the given method is *OpenImageIO* but the library is not available
writing will be performed by *Imageio*.
- If the given method is *Imageio*, ``kwargs`` is passed directly to the
wrapped definition.
- For convenience, single channel images are squeezed to 2D arrays.
Examples
--------
>>> import os
>>> import colour
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMS_Test_Pattern.exr')
>>> image = read_image(path)
>>> image.shape # doctest: +SKIP
(1267, 1274, 3)
>>> image.dtype
dtype('float32')
"""
method = validate_method(method, READ_IMAGE_METHODS)
if method == "openimageio": # pragma: no cover
if not is_openimageio_installed():
usage_warning(
'"OpenImageIO" related API features are not available, '
'switching to "Imageio"!'
)
method = "Imageio"
function = READ_IMAGE_METHODS[method]
if method == "openimageio": # pragma: no cover
kwargs = filter_kwargs(function, **kwargs)
return function(path, bit_depth, **kwargs)
[docs]@required("OpenImageIO")
def write_image_OpenImageIO(
image: ArrayLike,
path: str,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
attributes: Optional[Sequence] = None,
) -> Boolean: # noqa: D405,D407,D410,D411
"""
Write given image at given path using *OpenImageIO*.
Parameters
----------
image
Image data.
path
Image path.
bit_depth
Bit depth to write the image at, the bit depth conversion behaviour is
ruled directly by *OpenImageIO*.
attributes
An array of :class:`colour.io.ImageAttribute_Specification` class
instances used to set attributes of the image.
Returns
-------
:class:`bool`
Definition success.
Examples
--------
Basic image writing:
>>> import os
>>> import colour
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMS_Test_Pattern.exr')
>>> image = read_image(path) # doctest: +SKIP
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMSTestPattern.tif')
>>> write_image_OpenImageIO(image, path) # doctest: +SKIP
True
Advanced image writing while setting attributes:
>>> compression = ImageAttribute_Specification('Compression', 'none')
>>> write_image_OpenImageIO(image, path, 'uint8', [compression])
... # doctest: +SKIP
True
Writing an "ACES" compliant "EXR" file:
>>> if is_openimageio_installed(): # doctest: +SKIP
... from OpenImageIO import TypeDesc
... chromaticities = (
... 0.7347, 0.2653, 0.0, 1.0, 0.0001, -0.077, 0.32168, 0.33767)
... attributes = [
... ImageAttribute_Specification('acesImageContainerFlag', True),
... ImageAttribute_Specification(
... 'chromaticities', chromaticities, TypeDesc('float[8]')),
... ImageAttribute_Specification('compression', 'none')]
... write_image_OpenImageIO(image, path, attributes=attributes)
"""
from OpenImageIO import ImageOutput, ImageSpec
image = as_float_array(image)
path = str(path)
attributes = cast(List, optional(attributes, []))
bit_depth_specification = MAPPING_BIT_DEPTH[bit_depth]
if bit_depth_specification.numpy in [np.uint8, np.uint16]:
mininum, maximum = np.iinfo(np.uint8).min, np.iinfo(np.uint8).max
image = np.clip(image * maximum, mininum, maximum)
image = as_int_array(image, bit_depth_specification.numpy)
image = image.astype(bit_depth_specification.numpy)
if image.ndim == 2:
height, width = image.shape
channels = 1
else:
height, width, channels = image.shape
specification = ImageSpec(
width, height, channels, bit_depth_specification.openimageio
)
for attribute in attributes:
name = str(attribute.name)
value = (
str(attribute.value)
if isinstance(attribute.value, str)
else attribute.value
)
type_ = attribute.type_
if attribute.type_ is None:
specification.attribute(name, value)
else:
specification.attribute(name, type_, value)
image_output = ImageOutput.create(path)
image_output.open(path, specification)
image_output.write_image(image)
image_output.close()
return True
[docs]def write_image_Imageio(
image: ArrayLike,
path: str,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
**kwargs: Any,
) -> Boolean:
"""
Write given image at given path using *Imageio*.
Parameters
----------
image
Image data.
path
Image path.
bit_depth
Bit depth to write the image at, the image data is converted with
:func:`colour.io.convert_bit_depth` definition prior to writing the
image.
Other Parameters
----------------
kwargs
Keywords arguments.
Returns
-------
:class:`bool`
Definition success.
Examples
--------
>>> import os
>>> import colour
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMS_Test_Pattern.exr')
>>> image = read_image(path) # doctest: +SKIP
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMSTestPattern.tif')
>>> write_image_Imageio(image, path) # doctest: +SKIP
True
"""
from imageio import imwrite
image = convert_bit_depth(image, bit_depth)
return imwrite(path, image, **kwargs)
WRITE_IMAGE_METHODS: CaseInsensitiveMapping = CaseInsensitiveMapping(
{
"Imageio": write_image_Imageio,
"OpenImageIO": write_image_OpenImageIO,
}
)
WRITE_IMAGE_METHODS.__doc__ = """
Supported image write methods.
"""
[docs]def write_image(
image: ArrayLike,
path: str,
bit_depth: Literal[
"uint8", "uint16", "float16", "float32", "float64", "float128"
] = "float32",
method: Union[Literal["Imageio", "OpenImageIO"], str] = "OpenImageIO",
**kwargs: Any,
) -> Boolean: # noqa: D405,D407,D410,D411,D414
"""
Write given image at given path using given method.
Parameters
----------
image
Image data.
path
Image path.
bit_depth
Bit depth to write the image at, for the *Imageio* method, the image
data is converted with :func:`colour.io.convert_bit_depth` definition
prior to writing the image.
method
Write method, i.e. the image library used for writing images.
Other Parameters
----------------
attributes
{:func:`colour.io.write_image_OpenImageIO`},
An array of :class:`colour.io.ImageAttribute_Specification` class
instances used to set attributes of the image.
Returns
-------
:class:`bool`
Definition success.
Notes
-----
- If the given method is *OpenImageIO* but the library is not available
writing will be performed by *Imageio*.
- If the given method is *Imageio*, ``kwargs`` is passed directly to the
wrapped definition.
Examples
--------
Basic image writing:
>>> import os
>>> import colour
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMS_Test_Pattern.exr')
>>> image = read_image(path) # doctest: +SKIP
>>> path = os.path.join(colour.__path__[0], 'io', 'tests', 'resources',
... 'CMSTestPattern.tif')
>>> write_image(image, path) # doctest: +SKIP
True
Advanced image writing while setting attributes using *OpenImageIO*:
>>> compression = ImageAttribute_Specification('Compression', 'none')
>>> write_image(image, path, bit_depth='uint8', attributes=[compression])
... # doctest: +SKIP
True
"""
method = validate_method(method, WRITE_IMAGE_METHODS)
if method == "openimageio": # pragma: no cover
if not is_openimageio_installed():
usage_warning(
'"OpenImageIO" related API features are not available, '
'switching to "Imageio"!'
)
method = "Imageio"
function = WRITE_IMAGE_METHODS[method]
if method == "openimageio": # pragma: no cover
kwargs = filter_kwargs(function, **kwargs)
return function(image, path, bit_depth, **kwargs)