Monitor corrections

Support
1

Hi Chris,

I have some questions about how to perform visual display corrections.

Is there any lookup table that MWorks uses to make gamma corrections, or does it just assume that you’ve calibrated the monitor locally and use the native settings?

If it is all done natively, is there any way to impose corrections? For instance, I’d like to compensate for the asymmetry of pixel on/off times, which becomes important for stimuli with high temporal frequencies.

Thanks,
Lindsey.

2

Hi Lindsey,

Is there any lookup table that MWorks uses to make gamma corrections, or does it just assume that you’ve calibrated the monitor locally and use the native settings?

MWorks relies on the system color management settings and makes no attempt to alter them.

If it is all done natively, is there any way to impose corrections?

To be honest, this is a subject about which I know practically nothing, so I don’t think I can provide much of an answer to this question. Can you point me to another piece of software that makes the kind of corrections you want? (For example, do you mean something like this?) That could at least give me some clues as to what’s possible and how I might go about making it happen.

Thanks,
Chris

3

Chris,

Yes- that code in psychtoolbox will allow you to set a gamma table to make
adjustments along the contrast or color axis. There are also cases in
which you may make corrections along the axis of a different feature like
TF (in which you adjust the luminance of the stimulus to account for the
longer off transition for pixels since the error will increase with
increasing TF). In the past, I’ve done this manually (by setting
correction values at specific TFs), but it should/could probably be done
with a gamma table approach instead.

I’m not sure how general this issue is and I’m sure other Mworks users have
come up with solutions. I’ll talk a bit more with John and Mark, and then
come back to you if there’s something I need. But the most important thing
was to know that currently everything is done outside of Mworks.

Thanks,
Lindsey.