I am completely new to PTB and trying to set up my first experiment for showing images.
My aim is to display tiff-images (already color-graded in Rec.709) in the Rec.709 color space with a gamma of 2.4 on my external monitor via Screen(‘DrawTexture’).
So far I am not quite aware of the PTB imaging pipeline regarding the gamma and color conversions happening on the way to the monitor. I have tried to understand the PsychColorcorrection and Screen(‘LoadNormalizedGammaTable’) functions but due to the fact that I currently do not have access to proper calibration equipment I am not quite sure how to use these functions properly.
Could someone please give me a hint, if there’s a way to set up my pipeline easily and where to find a short description of the functionality of PTBs color pipeline regarding my problem?
Thank you very much in advance! I hope my question is understandable and not to vague or trivial.
My system is set up as follows:
GeForce RTX 3070
LG OLED C9 display connected via HDMI ultra high-speed cable to the graphics card
In addtion the current output of my screentests:
PTB-INFO: This is Psychtoolbox-3 for Microsoft Windows, under Matlab 64-Bit (Version 3.0.18 - Build date: May 18 2022).
PTB-INFO: OS support status: Windows 10 (Version 10.0) supported and tested to some limited degree.
PTB-INFO: Type ‘PsychtoolboxVersion’ for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file ‘License.txt’ in the Psychtoolbox root folder for the exact licensing conditions.
PTB-INFO: For information about paid support, community membership and commercial services, please type
PTB-INFO: The detected endline of the vertical blank interval is equal or lower than the startline. This indicates
PTB-INFO: that i couldn’t detect the duration of the vertical blank interval and won’t be able to correct timestamps
PTB-INFO: for it. This will introduce a very small and constant offset (typically << 1 msec). Read ‘help BeampositionQueries’
PTB-INFO: for how to correct this, should you really require that last few microseconds of precision.
PTB-INFO: Btw. this can also mean that your systems beamposition queries are slightly broken. It may help timing precision to
PTB-INFO: enable the beamposition workaround, as explained in ‘help ConserveVRAMSettings’, section ‘kPsychUseBeampositionQueryWorkaround’.
PTB-INFO: OpenGL-Renderer is NVIDIA Corporation :: NVIDIA GeForce RTX 3070/PCIe/SSE2 :: 4.6.0 NVIDIA 512.96
PTB-INFO: VBL startline = 2160 , VBL Endline = 2159
PTB-INFO: Measured monitor refresh interval from beamposition = 8.332255 ms [120.015529 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 8.333240 ms [120.001344 Hz]. (50 valid samples taken, stddev=0.038611 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 8.333333 ms [120.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-INFO: WINDOWS DWM DESKTOP COMPOSITOR IS ACTIVE. On this Windows-10 or later system, Psychtoolbox can no longer reliably detect if
PTB-INFO: this will cause trouble for timing and integrity of visual stimuli or not. You might be just fine, or you could be in trouble.
PTB-INFO: Use external measurement equipment and independent procedures to verify reliability of timing if you care about proper timing.
The refresh interval reported by the operating system is 8.33333 ms.
Measured refresh interval, as reported by “GetFlipInterval” is 8.33324 ms. (nsamples = 0, stddev = 0.00000 ms)
INFO: PTB’s Screen(‘Flip’, 10) command seems to have missed the requested stimulus presentation deadline
INFO: a total of 2 times out of a total of 607 flips during this session.
INFO: This number is fairly accurate (and indicative of real timing problems in your own code or your system)
INFO: if you provided requested stimulus onset times with the ‘when’ argument of Screen(‘Flip’, window [, when]);
INFO: If you called Screen(‘Flip’, window); without the ‘when’ argument, this count is more of a ‘‘mild’’ indicator
INFO: of timing behaviour than a hard reliable measurement. Large numbers may indicate problems and should at least
INFO: deserve your closer attention. Cfe. ‘help SyncTrouble’, the FAQ section at www.psychtoolbox.org and the
INFO: examples in the PDF presentation in PsychDocumentation/Psychtoolbox3-Slides.pdf for more info and timing tips.
PTB missed 2 out of 600 stimulus presentation deadlines.
One missed deadline is ok and an artifact of the measurement.
PTB completed 0 stimulus presentations before the requested target time.
Have a look at the plots for more details…