Hello PTB-Community,
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:
Windows 10
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: ‘PsychPaidSupportAndServices’.
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: ==============================================================================================================================
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.
PTB-INFO: ==============================================================================================================================
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…