Dataset and stimuli: "Importance of hue: color discrimination of three-dimensional objects and two-dimensional discs"

This dataset contains observer data and stimulus information for the below publication. Refer to this manuscript for more details. Please cite this manuscript if you choose to use any portion of this dataset.

Laysa Hedjar, Matteo Toscani, and Karl R. Gegenfurtner, "The importance of hue: color discrimination of three-dimensional objects and two-dimensional discs," Journal of the Optical Society of American A 42(5), 1-9 (2025), doi:10.1364/JOSAA.544380

Experimental participant data is available in thresholds.csv: 

ptID: participant ID number

JND (DT units): just-noticable difference threshold in detection threshold units

stimulus type: 3D blob stimulus or 2D disc stimulus

quadrant: quadrant of DKL color space

color dimension: dimension of color difference (hue or chroma)

direction: direction of color difference (increasing or decreasing for chroma, clockwise [cw] or counter-clockwise [ccw] for hue)

Participant data used to scale DKL color space is available in detection_thresholds.csv:

ptID: participant ID number

JND (arbitrary DKL units): just-noticable detection threshold

angle: angle measured in DKL color space (Angle 0 is the positive L-M axis, Angle 90 is the positive S-(L+M) axis)

Stimuli (blob only) are available in stimImages.mat. None of the stimuli are gamma-corrected.

rooms.empty: 5000 x 1000 x 3 single; image presented between 3D blob trials

rooms.empty_shadow: 5000 x 1000 x 3 single; base image on which stimuli were pasted

blobs: 400 x 250 x 3 x 31 x 2 x 4 x 4 x 4 single; blob stimuli used in experiment

blobs(:, :, :, iShift, iHC, iQuad, iPos, iRot), where:

iShift indexes equally spaced shifts in DKL of the odd disc relative to the reference color. Values 1-15 approach the reference from one direction (ex. decreasing chroma), value 16 is the reference color, and values 17-31 move away from the reference in the opposite direction (ex. increasing chroma).

iHC: 1 = hue shift, 2 = chroma shift

iQuad: quadrant in DKL space; 1 = +(S-LM), +LM (purplish); 2 = +(S-LM), -LM (bluish); 3 = -(S-LM), -LM (greenish); 4 = -(S-LM), +LM (orangish)

iPos: position of odd disc in layout (counterclockwise)

iRot: one of four sets of blob rotations

Each of these stimulus images should replace the base image at the following base image pixel locations:

Y: 101:500

X: 376:625