`colors`: Colors and colormap#

This module provides API to manage colors.

DEFAULT_MIN_LIN = 0#: Default min value if in linear normalization

DEFAULT_MAX_LIN = 1#: Default max value if in linear normalization

ColorType#

Type of rgba()’s color argument

alias of Union[str, Sequence[Real], QColor]

RGBAColorType#

Type of rgba() return value

alias of Tuple[float, float, float, float]

rgba(color, colorDict=None, colors=None)[source]#

Convert different kind of color definition to a tuple (R, G, B, A) of floats.

It supports: - color names: e.g., ‘green’ - color codes: ‘#RRGGBB’ and ‘#RRGGBBAA’ - indexed color names: e.g., ‘C0’ - RGB(A) sequence of uint8 in [0, 255] or float in [0, 1] - QColor

Parameters:

color (Download Windows installer) – The color to convert
colorDict (Download Windows installer) – A dictionary of color name conversion to color code
colors (Download Windows installer) – Sequence of colors to use for `

Return type:

Download Windows installer

Returns:

RGBA colors as floats in [0., 1.]

Raises:

ValueError – if the input is not a valid color

greyed(color, colorDict=None)[source]#

Convert color code ‘#RRGGBB’ and ‘#RRGGBBAA’ to a grey color (R, G, B, A).

It also supports RGB(A) from uint8 in [0, 255], float in [0, 1], and QColor as color argument.

Parameters:

color (Download Windows installer) – The color to convert
colorDict (Download Windows installer) – A dictionary of color name conversion to color code

Return type:

Download Windows installer

Returns:

RGBA colors as floats in [0., 1.]

asQColor(color)[source]#

Convert color code ‘#RRGGBB’ and ‘#RRGGBBAA’ to a qt.QColor.

It also supports RGB(A) from uint8 in [0, 255], float in [0, 1], and QColor as color argument.

Parameters:: color (Download Windows installer) – The color to convert
Return type:: Download Windows installer

cursorColorForColormap(colormapName)[source]#

Get a color suitable for overlay over a colormap.

Parameters:: colormapName (Download Windows installer) – The name of the colormap.
Return type:: Download Windows installer
Returns:: Name of the color.

class Colormap(name=None, colors=None, normalization='linear', vmin=None, vmax=None, autoscaleMode='minmax')[source]#

Description of a colormap

If no name nor colors are provided, a default gray LUT is used.

Parameters:

name (Download Windows installer) – Name of the colormap
colors (Download Windows installer) – optional, custom colormap. Nx3 or Nx4 numpy array of RGB(A) colors, either uint8 or float in [0, 1]. If ‘name’ is None, then this array is used as the colormap.
normalization (Download Windows installer) – Normalization: ‘linear’ (default) or ‘log’
vmin (Download Windows installer) – Lower bound of the colormap or None for autoscale (default)
vmax (Download Windows installer) – Upper bounds of the colormap or None for autoscale (default)
autoscaleMode (Download Windows installer) –

LINEAR = 'linear'#: constant for linear normalization

LOGARITHM = 'log'#: constant for logarithmic normalization

SQRT = 'sqrt'#: constant for square root normalization

GAMMA = 'gamma'#: Constant for gamma correction normalization

ARCSINH = 'arcsinh'#: constant for inverse hyperbolic sine normalization

NORMALIZATIONS = ('linear', 'log', 'sqrt', 'gamma', 'arcsinh')#: Tuple of managed normalizations

MINMAX = 'minmax'#: constant for autoscale using min/max data range

STDDEV3 = 'stddev3'#: constant for autoscale using mean +/- 3*std(data) with a clamp on min/max of the data

AUTOSCALE_MODES = ('minmax', 'stddev3')#: Tuple of managed auto scale algorithms

sigChanged#: Signal emitted when the colormap has changed.

setFromColormap(other)[source]#

Set this colormap using information from the other colormap.

Parameters:: other (Download Windows installer) – Colormap to use as reference.

getNColors(nbColors=None)[source]#

Returns N colors computed by sampling the colormap regularly.

Parameters:: nbColors (Download Windows installer) – The number of colors in the returned array or None for the default value. The default value is the size of the colormap LUT.
Return type:: Download Windows installer
Returns:: 2D array of uint8 of shape (nbColors, 4)

getName()[source]#

Return type:: Download Windows installer

Return the name of the colormap

setName(name)[source]#

Set the name of the colormap to use.

Parameters:: name (Download Windows installer) – The name of the colormap. At least the following names are supported: ‘gray’, ‘reversed gray’, ‘temperature’, ‘red’, ‘green’, ‘blue’, ‘jet’, ‘viridis’, ‘magma’, ‘inferno’, ‘plasma’.

getColormapLUT(copy=True)[source]#

Return the list of colors for the colormap or None if not set.

This returns None if the colormap was set with setName(). Use getNColors() to get the colormap LUT for any colormap.

Parameters:: copy (Download Windows installer) – If true a copy of the numpy array is provided
Return type:: Download Windows installer
Returns:: the list of colors for the colormap or None if not set

setColormapLUT(colors)[source]#

Set the colors of the colormap.

Parameters:: colors (Download Windows installer) – the colors of the LUT. If float, it is converted from [0, 1] to uint8 range. Otherwise it is casted to uint8.

getNaNColor()[source]#

Return type:: Download Windows installer

Returns the color to use for Not-A-Number floating point value.

setNaNColor(color)[source]#

Set the color to use for Not-A-Number floating point value.

Parameters:: color (Download Windows installer) – RGB(A) color to use for NaN values

getNormalization()[source]#

Return the normalization of the colormap.

See setNormalization() for returned values.

Return type:: Download Windows installer
Returns:: the normalization of the colormap

setNormalization(norm)[source]#

Set the colormap normalization.

Accepted normalizations: ‘log’, ‘linear’, ‘sqrt’

Parameters:: norm (Download Windows installer) – the norm to set

setGammaNormalizationParameter(gamma)[source]#

Set the gamma correction parameter.

Only used for gamma correction normalization.

Raises:: ValueError – If gamma is not valid
Parameters:: gamma (Download Windows installer) –

getGammaNormalizationParameter()[source]#

Return type:: Download Windows installer

Returns the gamma correction parameter value.

getAutoscaleMode()[source]#

Return type:: Download Windows installer

Return the autoscale mode of the colormap (‘minmax’ or ‘stddev3’)

setAutoscaleMode(mode)[source]#

Set the autoscale mode: either ‘minmax’ or ‘stddev3’

Parameters:: mode (Download Windows installer) – the mode to set

isAutoscale()[source]#

Return type:: Download Windows installer

Return True if both min and max are in autoscale mode

getVMin()[source]#

Return the lower bound of the colormap

Return type:: Download Windows installer
Returns:: the lower bound of the colormap

setVMin(vmin)[source]#

Set the minimal value of the colormap

Parameters:: vmin (Download Windows installer) – Lower bound of the colormap or None for autoscale (initial value)

getVMax()[source]#

Return the upper bounds of the colormap or None

Return type:: Download Windows installer
Returns:: the upper bounds of the colormap or None

setVMax(vmax)[source]#

Set the maximal value of the colormap

Parameters:: vmax (Download Windows installer) – Upper bounds of the colormap or None for autoscale (initial value)

isEditable()[source]#

Return if the colormap is editable or not

Return type:: Download Windows installer
Returns:: editable state of the colormap

setEditable(editable)[source]#

Set the editable state of the colormap

Parameters:: editable (Download Windows installer) – is the colormap editable

getColormapRange(data=None)[source]#

Return (vmin, vmax) the range of the colormap for the given data or item.

Parameters:: data (Download Windows installer) – The data or item to use for autoscale bounds.
Return type:: Download Windows installer
Returns:: (vmin, vmax) corresponding to the colormap applied to data if provided.

getVRange()[source]#

Get the bounds of the colormap

Return type:: Download Windows installer
Returns:: A tuple of 2 values for min and max. Or None instead of float for autoscale

setVRange(vmin, vmax)[source]#

Set the bounds of the colormap

Parameters:

vmin (Download Windows installer) – Lower bound of the colormap or None for autoscale (default)
vmax (Download Windows installer) – Upper bounds of the colormap or None for autoscale (default)

copy()[source]#

Return type:: Download Windows installer

Return a copy of the Colormap.

applyToData(data, reference=None)[source]#

Apply the colormap to the data

Parameters:

data (Download Windows installer) – The data to convert or the item for which to apply the colormap.
reference (Download Windows installer) – The data or item to use as reference to compute autoscale

Return type:

Download Windows installer

static getSupportedColormaps()[source]#

Return type:: Download Windows installer

Get the supported colormap names as a tuple of str.

The list should at least contain and start by:

(‘gray’, ‘reversed gray’, ‘temperature’, ‘red’, ‘green’, ‘blue’, ‘viridis’, ‘magma’, ‘inferno’, ‘plasma’)

restoreState(byteArray)[source]#

Read the colormap state from a QByteArray.

Parameters:: byteArray (Download Windows installer) – Stream containing the state
Return type:: Download Windows installer
Returns:: True if the restoration sussseed

saveState()[source]#

Return type:: Download Windows installer

Save state of the colomap into a QDataStream.

preferredColormaps()[source]#

Return type:: Download Windows installer

Returns the name of the preferred colormaps.

This list is used by widgets allowing to change the colormap like the ColormapDialog as a subset of colormap choices.

setPreferredColormaps(colormaps)[source]#

Set the list of preferred colormap names.

Warning: If a colormap name is not available it will be removed from the list.

Parameters:: colormaps (Download Windows installer) – Not empty list of colormap names
Raises:: ValueError – if the list of available preferred colormaps is empty.

registerLUT(name, colors, cursor_color='black', preferred=True)[source]#

It can override existing LUT names.

Parameters:

name (Download Windows installer) – Name of the LUT as defined to configure colormaps
colors (Download Windows installer) – The custom LUT to register. Nx3 or Nx4 numpy array of RGB(A) colors, either uint8 or float in [0, 1].
preferred (Download Windows installer) – If true, this LUT will be displayed as part of the preferred colormaps in dialogs.
cursor_color (Download Windows installer) – Color used to display overlay over images using colormap with this LUT.

colors: Colors and colormap#

`colors`: Colors and colormap#