cutcutcodec.core.classes.colorspace.Colorspace

class cutcutcodec.core.classes.colorspace.Colorspace(space: str | Self, primaries: str | None = None, transfer: str | None = None)

Structure to ensure color space consistency.

See cutcutcodec.core.colorspace for more details and explanations.

Attributes

color_primariesint

The ffmpeg primaries code.

color_trcint

The ffmpeg transfere function.

primariesstr or None

The tristimulus primaries colors name (gamut). All available values are the keys of cutcutcodec.core.colorspace.cst.PRIMARIES, defined in the module cutcutcodec.core.colorspace.cst.

spacestr

The main space name, one of « y’pbpr », « r’g’b” », « rgb », « xyz ». It is defined in cutcutcodec.core.colorspace.cst.SYMBS.

symbolstuple[sympy.Symbol, sympy.Symbol, sympy.Symbol]

The sympy symbols used as input of the expression given by the methode to.

transferstr or None

The non-linear transfer function name (gamma). All available values are the keys of cutcutcodec.core.colorspace.cst.TRC, defined in the module cutcutcodec.core.colorspace.cst.

Parse the colorspace.

Parameters

spaceColorspace | str

The colorspace formatted as {name}[_{colorspace}], with name in « y’pbpr », « r’g’b” », « rgb », « xyz » (readonly). When several names are given, the first matching in alphabetic order is taken.

primariesstr, optional

If supplied, this is given priority over space for the gamut (read and write).

transferstr, optional

If supplied, this is given priority over space for the gamma (read and write).

property color_primaries: int

Return the ffmpeg code for the flag -color_primaries.

Examples

>>> from cutcutcodec.core.classes.colorspace import Colorspace
>>> Colorspace("r'g'b'", "bt2020", "bt2020").color_primaries
9
>>>

property color_trc: int

Return the ffmpeg code for the flag -color_trc.

Examples

>>> from cutcutcodec.core.classes.colorspace import Colorspace
>>> Colorspace("r'g'b'", "bt2020", "bt2020").color_trc
1
>>>

classmethod from_default_target() → Self

Create the default y’pbpr working colorspace.

The default primaries and transfer are taken from the attributes target_prim and target_trc of the class cutcutcodec.config.config.Config.

The default value can be overwitten in the file ~/.config/cutcutcodec/conf.ini

Examples

>>> from cutcutcodec.core.classes.colorspace import Colorspace
>>> Colorspace.from_default_target()
Colorspace("y'pbpr", 'bt709', 'iec61966-2-1, iec61966_2_1')
>>>

classmethod from_default_target_rgb() → Self

Construct same as from_default_target in r’g’b” space.

classmethod from_default_working() → Self

Create the default rgb working colorspace.

The default primaries is taken from the attribute working_prim of the class cutcutcodec.config.config.Config.

The default value can be overwitten in the file ~/.config/cutcutcodec/conf.ini

Examples

>>> from cutcutcodec.core.classes.colorspace import Colorspace
>>> Colorspace.from_default_working()
Colorspace('rgb', 'bt709')
>>>

property primaries: None | str

Return the gamut name.

property space: str

Return the main colorspace name.

property symbols: tuple[Symbol, Symbol, Symbol]

Return the space symbols.

to_equation(dst: Self | str) → tuple[Basic, Basic, Basic]

Find the symbolic expressions of the colorspace conversion.

Attributes

dstColorspace or str

The target colorspace, transmitted to cutcutcodec.core.colorspace.func.convert().

Returns

channel_1, channel_2, channel_3sympy.core.basic.Basic

Symbolic expressions for each channel.

to_function(dst: Self | str) → callable

Compile the colorspace conversion function.

Attributes

dstColorspace or str

The target colorspace, transmitted to cutcutcodec.core.colorspace.func.convert().

Returns

funccallable

The function that eats 3 channels in source space and sends them back to target space.

Examples

>>> import torch
>>> from cutcutcodec.core.classes.colorspace import Colorspace
>>> src, dst = Colorspace("rgb", "smpte240m"), Colorspace("y'pbpr", "bt709", "gamma22")
>>> func = src.to_function(dst)
>>> r, g, b = torch.rand(1080, 1920), torch.rand(1080, 1920), torch.rand(1080, 1920)
>>> y, u, v = func(r=r, g=g, b=b)
>>>

property transfer: None | str

Return the gamut name.