Source code for colour.io.image

"""
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,
    tstack,
    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",
    "as_3_channels_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 data 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 data 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 data 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 data 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 data 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 data 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)
[docs]def as_3_channels_image(a: ArrayLike) -> NDArray: """ Convert given array :math:`a` to a 3-channels image-like representation. Parameters ---------- a Array :math:`a` to convert to a 3-channels image-like representation. Returns ------- :class`numpy.ndarray` 3-channels image-like representation of array :math:`a`. Examples -------- >>> as_3_channels_image(0.18) array([[[ 0.18, 0.18, 0.18]]]) >>> as_3_channels_image([0.18]) array([[[ 0.18, 0.18, 0.18]]]) >>> as_3_channels_image([0.18, 0.18, 0.18]) array([[[ 0.18, 0.18, 0.18]]]) >>> as_3_channels_image([[0.18, 0.18, 0.18]]) array([[[ 0.18, 0.18, 0.18]]]) >>> as_3_channels_image([[[0.18, 0.18, 0.18]]]) array([[[ 0.18, 0.18, 0.18]]]) """ a = as_float_array(a) if len(a.shape) == 0: a = tstack([a, a, a]) if a.shape[-1] == 1: a = tstack([a, a, a]) if len(a.shape) == 1: a = a[np.newaxis, np.newaxis, ...] elif len(a.shape) == 2: a = a[np.newaxis, ...] return a