ImageView

class pyqtgraph.ImageView(parent=None, name='ImageView', view=None, imageItem=None, levelMode='mono', *args)

Widget used for display and analysis of image data. Implements many features:

• Displays 2D and 3D image data. For 3D data, a z-axis slider is displayed allowing the user to select which frame is displayed.

• Displays histogram of image data with movable region defining the dark/light levels

• Editable gradient provides a color lookup table

• Frame slider may also be moved using left/right arrow keys as well as pgup, pgdn, home, and end.

• Basic analysis features including:

  • ROI and embedded plot for measuring image values across frames

  • Image normalization / background subtraction

Basic Usage:

imv = pg.ImageView()
imv.show()
imv.setImage(data)

Keyboard interaction

• left/right arrows step forward/backward 1 frame when pressed, seek at 20fps when held.

• up/down arrows seek at 100fps

• pgup/pgdn seek at 1000fps

• home/end seek immediately to the first/last frame

• space begins playing frames. If time values (in seconds) are given for each frame, then playback is in realtime.

__init__(parent=None, name='ImageView', view=None, imageItem=None, levelMode='mono', *args)

By default, this class creates an ImageItem to display image data and a ViewBox to contain the ImageItem.

Arguments
parent	(QWidget) Specifies the parent widget to which this ImageView will belong. If None, then the ImageView is created with no parent.
name	(str) The name used to register both the internal ViewBox and the PlotItem used to display ROI data. See the name argument to ViewBox.__init__().
view	(ViewBox or PlotItem) If specified, this will be used as the display area that contains the displayed image. Any ViewBox, PlotItem, or other compatible object is acceptable.
imageItem	(ImageItem) If specified, this object will be used to display the image. Must be an instance of ImageItem or other compatible object.
levelMode	See the levelMode argument to HistogramLUTItem.__init__()

Note: to display axis ticks inside the ImageView, instantiate it with a PlotItem instance as its view:

pg.ImageView(view=pg.PlotItem())

autoLevels()

Set the min/max intensity levels automatically to match the image data.

autoRange()

Auto scale and pan the view around the image such that the image fills the view.

close()

Closes the widget nicely, making sure to clear the graphics scene and release memory.

export(fileName)

Export data from the ImageView to a file, or to a stack of files if the data is 3D. Saving an image stack will result in index numbers being added to the file name. Images are saved as they would appear onscreen, with levels and lookup table applied.

getHistogramWidget()

Return the HistogramLUTWidget for this ImageView

getImageItem()

Return the ImageItem for this ImageView.

getProcessedImage()

Returns the image data after it has been processed by any normalization options in use.

getRoiPlot()

Return the ROI PlotWidget for this ImageView

getView()

Return the ViewBox (or other compatible object) which displays the ImageItem

jumpFrames(n)

Move video frame ahead n frames (may be negative)

normalize(image)

Process image using the normalization options configured in the control panel.

This can be repurposed to process any data through the same filter.

play(rate=None)

Begin automatically stepping frames forward at the given rate (in fps). This can also be accessed by pressing the spacebar.

quickMinMax(data)

Estimate the min/max values of data by subsampling. Returns [(min, max), …] with one item per channel

setColorMap(colormap)

Set the color map.

Arguments
colormap	(A ColorMap() instance) The ColorMap to use for coloring images.

setCurrentIndex(ind)

Set the currently displayed frame index.

setImage(img, autoRange=True, autoLevels=True, levels=None, axes=None, xvals=None, pos=None, scale=None, transform=None, autoHistogramRange=True, levelMode=None)

Set the image to be displayed in the widget.

Arguments:
img	(numpy array) the image to be displayed. See ImageItem.setImage() and notes below.
xvals	(numpy array) 1D array of z-axis values corresponding to the first axis in a 3D image. For video, this array should contain the time of each frame.
autoRange	(bool) whether to scale/pan the view to fit the image.
autoLevels	(bool) whether to update the white/black levels to fit the image.
levels	(min, max); the white and black level values to use.
axes	Dictionary indicating the interpretation for each axis. This is only needed to override the default guess. Format is: {'t':0, 'x':1, 'y':2, 'c':3};
pos	Change the position of the displayed image
scale	Change the scale of the displayed image
transform	Set the transform of the displayed image. This option overrides pos and scale.
autoHistogramRange	If True, the histogram y-range is automatically scaled to fit the image data.
levelMode	If specified, this sets the user interaction mode for setting image levels. Options are ‘mono’, which provides a single level control for all image channels, and ‘rgb’ or ‘rgba’, which provide individual controls for each channel.

Notes:

For backward compatibility, image data is assumed to be in column-major order (column, row). However, most image data is stored in row-major order (row, column) and will need to be transposed before calling setImage():

imageview.setImage(imagedata.T)

This requirement can be changed by the imageAxisOrder global configuration option.

setLevels(*args, **kwds)

Set the min/max (bright and dark) levels.

See HistogramLUTItem.setLevels.

setPredefinedGradient(name)

Set one of the gradients defined in GradientEditorItem. Currently available gradients are: ‘thermal’, ‘flame’, ‘yellowy’, ‘bipolar’, ‘spectrum’, ‘cyclic’, ‘greyclip’, ‘grey’, ‘viridis’, ‘inferno’, ‘plasma’, ‘magma’