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Can I use a constant background image throughout an experiment?

Hi guys,
I’m looking to add a constant background (a frame around the stims) to every trial of an experiment and to the instructions. It’d be a pain to add the image to each routine with visual.ImageStim(), so I’m wondering if there’s a quick way to specify a background when setting up the window instead?

This sounds like Builder but you put it in the Code category. So I’m answering for both :slight_smile:

You cannot set a background picture in the window object itself. But you could use the autoDraw property of many stimuli to always draw it. So:

background_image = visual.ImageStim(win, 'my_folder/my_image.png', autoDraw=True)

If this is Builder, do it in a Code component which runs on “Begin Experiment”. If you want to turn it on or off some time during your experiment, just do:

background_image.autoDraw = False  # Turns off
background_image.autoDraw = True  # Turns on (again)

Ah that’s exactly what I was after; thanks for the quick reply!

Hi @TZK ,

Can you share more info?

Did follow the above guidelines but got this error:
Traceback (most recent call last):
File “\PsychoPy\TestExperiment1\”, line 31, in
background_image = visual.ImageStim(win, ‘novel191.bmp’, autoDraw=True)
NameError: name ‘win’ is not defined

Any clues how to move on?

Hi @Sharon.Psy,

To be honest, I didn’t remember which experiment my original question was in reference to, but I did find one on my computer from four years ago where I successfully added a white boarder around the stimuli. In case it helps, here’s how it looked, which seems to be a combo of both of the above suggestions. I used builder in PsychoPy2 and inserted a code component which had this under the “begin experiment” tab:

background_image = visual.ImageStim(win, 'Frame.png')

Where “Frame.png” was in the same directory as the .psyexp file.

Then I turned it on or off with a separate code chunk in each routine by adding this under the “begin routine” tab:

background_image.autoDraw = True
background_image.autoDraw = False