Changing the colormap for cameragui

[mario-b-amaro]

How could one change the colormap of camera_gui? The default seems to be 'inferno', however it would be nice if it would be possible to change it. I initially thought it could be changed 'camera_logic.py', in the function draw_3d_image. Sadly, even after changing the cmap there and reseting qudi, the camera_gui still plots the camera image in the default colormap. Does anyone know the way to do it? Thank you!

[Neverhorst]

Hi @mario-b-amaro ,

The plotting code you can find in any logic module is just responsible for creating a thumbnail image using matplotlib that is saved to file alongside the measurement data. matplotlib has a nice interface to set the colorscale via keyword (inferno, rainbow etc.). But the plotting widgets of the GUI modules do not use matplotlib but Qt for Python (PySide2).
Currently there is no concise interface to change the colorscale of a GUI plotwidget (from qudi.util.widgets.plotting) via a simple function call. It would be nice to have this functionality, so feel free to file a feature request in qudi-core.

If you really need to change the colorscale now, you can do it the ugly way by altering qudi.gui.camera.cameragui; more specifically by appending the following lines to the CameraMainWindow.__init__. However I advise against such quick-and-dirty changes to the code because they are non-maintainable and cause your code to diverge from the upstream repository. It's better to fix this in qudi-core and make it generally configurable.

self.image_widget.image_item.setLookupTable(ColorScaleViridis().lut)
grad = QtGui.QLinearGradient(0, 0, 0, 1)
grad.setCoordinateMode(QtGui.QGradient.ObjectMode)
for stop, color in zip(*ColorScaleViridis().colormap.getStops('byte')):
    grad.setColorAt(stop, QtGui.QColor(*color))
self.image_widget.colorbar_widget.colorbar.setOpts(brush=QtGui.QBrush(grad))

ColorScaleViridis is just an example of a colorscale imported from qudi.util.colordefs. If the colorscale you want can not be found in this module, you can create your own by subclassing qudi.util.colordefs.ColorScale and providing the COLORS class attribute. Have a look at the module in qudi-core to see how this is done.