ColorBarItem

class pyqtgraph.ColorBarItem(values=(0, 1), width=25, colorMap=None, label=None, interactive=True, limits=None, rounding=1, orientation='vertical', pen='w', hoverPen='r', hoverBrush='#FF000080', cmap=None)

Bases: PlotItem

ColorBarItem controls the application of a color map to one (or more) ImageItem. It is a simpler, compact alternative to HistogramLUTItem, without histogram or the option to adjust the colors of the look-up table.

A labeled axis is displayed directly next to the gradient to help identify values. Handles included in the color bar allow for interactive adjustment.

A ColorBarItem can be assigned one or more GraphicsLayout or added to the layout of a PlotItem used to display image data with coordinate axes.

Signals:
sigLevelsChanged(self)	Emitted when the range sliders are moved
sigLevelsChangeFinished(self)	Emitted when the range sliders are released

__init__(values=(0, 1), width=25, colorMap=None, label=None, interactive=True, limits=None, rounding=1, orientation='vertical', pen='w', hoverPen='r', hoverBrush='#FF000080', cmap=None)

Creates a new ColorBarItem.

Parameters

• colorMap (str or ColorMap) – Determines the color map displayed and applied to assigned ImageItem(s).

• values (tuple of float) – The range of image levels covered by the color bar, as (min, max).

• width (float, default=25) – The width of the displayed color bar.

• label (str, optional) – Label applied to the color bar axis.

• interactive (bool, default=True) – If True, handles are displayed to interactively adjust the level range.

• limits (None or tuple of float) – Limits the adjustment range to (low, high), None disables the limit.

• rounding (float, default=1) – Adjusted range values are rounded to multiples of this value.

• orientation (str, default 'vertical') – ‘horizontal’ or ‘h’ gives a horizontal color bar instead of the default vertical bar

• pen (Qpen or argument to mkPen()) – Sets the color of adjustment handles in interactive mode.

• hoverPen (QPen or argument to mkPen()) – Sets the color of adjustement handles when hovered over.

• hoverBrush (QBrush or argument to mkBrush()) – Sets the color of movable center region when hovered over.

colorMap()

Returns the assigned ColorMap object.

levels()

Returns the currently set levels as the tuple (low, high).

setColorMap(colorMap)

Sets a color map to determine the ColorBarItem’s look-up table. The same look-up table is applied to any assigned ImageItem.

colorMap can be a ColorMap or a string argument that is passed to colormap.get().

setImageItem(img, insert_in=None)

Assigns an ImageItem or list of ImageItems to be represented and controlled

Parameters

• image (ImageItem or list of [ImageItem, ImageItem, …]) – Assigns one or more ImageItems to this ColorBarItem. If a ColorMap is defined for ColorBarItem, this will be assigned to the ImageItems. Otherwise, the ColorBarItem will attempt to retrieve a color map from the ImageItems. In interactive mode, ColorBarItem will control the levels of the assigned ImageItems, simultaneously if there is more than one.

• insert_in (PlotItem, optional) – If a PlotItem is given, the color bar is inserted on the right or bottom of the plot, depending on the specified orientation.

setLevels(values=None, low=None, high=None)

Sets the displayed range of image levels.

Parameters

• values (tuple of float) – Specifies levels as tuple (low, high). Either value can be None to leave the previous value unchanged. Takes precedence over low and high parameters.

• low (float) – Applies a new low level to color bar and assigned images

• high (float) – Applies a new high level to color bar and assigned images