Color Constancy in a Naturalistic Goal-Directed Task
Supplemental Material
Ana Radonjić, Nicolas P. Cottaris & David H. Brainard
Experimental instructions
- Instructions (pdf)
- Note: Experimental intstructions are slighly modified after
Experiment 1. Sections of instructions added at this point are marked
in italics.
Stimulus geometry
Blender files specifying the position of each element in each of the stimulus scenes:
(NOTE: Blender is required to view these files).
Experiments 1 and 2: Model/Workspace Source
Experiment 3: Model/Workspace Source
Stimulus colorimetry
- Illuminants used for rendering. Spectral power distribution for each simulated illuminant as
tab delimited text.
- Table format: 1st column: wavelength in nm (380 - 780 nm, 5 nm
steps); 2nd column: illuminant spectrum.
- Different spectral sampling was used for rendering (400 - 700 nm, 10 nm steps).
Experiments 1 and 2-Set A: Standard(6500°K), Bluish(12000°K)
Experiments 3 and 2-Set B: Standard(6500°K), Yellowish(4500°K), Bluish(12000°K)
Illuminant spectra impinging on the blocks.
These values are extracted from images in which the blocks were rendered as perfectly reflective surfaces.
Following the methods described in the paper, we used these illuminant
values to: (1) compute the reflectance of competitors (2nd block from
the left served as the standard), (2) compute the reflectances of
blocks in basis images (mean across blocks used as the standard) and
(3) compute the desired RGB values for a chosen block of certain
reflectance that is moved to a certain block location in the workspace
(these values are used as input for synthesizing the chosen block in
the workspace).
Table format: 1st
column: wavelength in nm (380 - 780 nm, 5 nm
steps); Columns 2-5: illuminant spectrum impinging on each of the four
blocks (from leftmost in column 2 to rightmost in column 4).
Experiments 1 and 2-Set A: Standard(6500°K), Bluish(12000°K)
Experiment 2-Set B: Standard(6500°K), Yellowish(4500°K), Bluish(12000°K)
Experiments 3: Standard(6500°K), Bluish(12000°K)
Targets. Simulated surface reflectance as tab delimited text.
Table format: 1st column: wavelength in nm (400 - 700 nm, 10 nm steps); 2nd column: spectral reflectance.
The same spectral sampling was used for rendering.
- Experiments 1 and 2-SetA: Gray (T1), Rose
(T2), Teal (T3), Green (T4).
- Experiment 2-Set B: Corn (T1), Skin (Caucasian, T2), Lettuce (T3), Tree bark (T4).
- Experiment 3: Straw(T1). T2-T4 were the same as in Experiment 2-SetB.
- Competitor sets. Simulated surface reflectance for competitor is provided for each experiment and condition as tab delimited text.
Table format: 1st column: wavelength in nm (400 - 700 nm, 10 nm steps). Remaining columns: spectral reflectance for each competitor (competitor labels are denoted in the first row).
- Competitor notation is the same as that used in
Figure 2.
- Experiments 1 and 2-Set A: Illuminant-constant, Illuminant-change (bluish).
- Experiments 2-Set B: Illuminant-constant, Illuminant-change (yellowish), Illuminant-change (bluish).
-
Experiment 3: Illuminant-constant, Illuminant-change (bluish).
- CIELAB and xyY values of each target and its competitor set are tabulated for each
illumination condition. Competitor notation is the same as that used in
Figure 2. For each set we also provide a white point used for conversion.
- Experiments 1 and 2-Set A: Target and competitor blocks (CIELAB and xyY)
- Experiments 2-Set B: Target and competitor blocks (CIELAB and xyY)
-
Experiment 3: Target and competitor blocks (CIELAB and xyY)
CIELAB Distance table provides distances in (delta E) between adjacent competitors in a set for all experiments and conditions (pdf).
Individual Observer Data
- Experiment 1: DLV, NIT, KJF, CTG.
- Experiment 2A: LTD, IEA, HGC, LDO, EAZ, VSR.
- Experiment 2B: LTD, IEA, LDO, EAZ, VSR.
- Experiment 3: SED, MGO, ITY, BSW, NKJ, GTH.
Preliminary experiment for Experiment 3 - methods and results (pdf)