feature request: bit-stealing option for DriftingGrating

mhisted's Avatar

mhisted

07 Nov, 2013 05:34 PM

Hi Chris,

It would be nice if the drifting grating stimulus had an option to do ~10-bit grayscale on a normal monitor using "bitstealing" - changing the RGB channels each slightly around each 8-bit gray level. Here's a description of a modern use of the technique:
http://r0k.us/graphics/PseudoGreyPlus.html

I'm not 100% sure how this would interact with a linearized-gamma color profile, as we typically use for zero-luminance-step contrast changes, but we could check.

This is low priority for me, but I bet several labs would use it (everyone who uses low contrast grayscale stimuli). Probably worth putting in the request queue, however.

Thanks,
Mark

  1. 1 Posted by mhisted on 07 Nov, 2013 05:43 PM

    mhisted's Avatar

    One more bit of info:

    Psychtoolbox supports a wide variety of methods to achieve greater than 8-bit gray intensities.
    http://docs.psychtoolbox.org/AdditiveBlendingForLinearSuperpositionTutorial

    Hard-core applications will use custom hardware such as Bits-sharp with a CRT:
    http://www.crsltd.com/tools-for-vision-science/visual-stimulation/bits-sharp-visual-stimulus-processor/
    Which we don't need now.

    But the equivalent to the PsychToolbox 'PseudoGray' display driver would be nice to have.

    Mark

  2. Support Staff 2 Posted by Christopher Sta... on 12 Nov, 2013 05:02 PM

    Christopher Stawarz's Avatar

    Hi Mark,

    I've opened a ticket for this.

    Cheers,
    Chris

  3. Christopher Stawarz closed this discussion on 19 Nov, 2013 03:39 PM.

  4. Christopher Stawarz closed this discussion on 28 Nov, 2018 03:50 PM.

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