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Synthetic Data for Computatational Colour Constancy Experiments

The official source for this data is elsewhere, and the the appropriate web resource reference to the data is one of
However, the associated meta data is likely to be corrected/updated more frequently in this version of the interface.

Questions, comments, and problems with this data should be directed to Kobus Barnard

This directory contains some the data presented in:

Kobus Barnard, Lindsay Martin, Brian Funt, and Adam Coath, " Data for Colour Research," Color Research and Application, Volume 27, Issue 3, pp. 148-152, 2002.

(The appropriate archival reference for this data).

This data in this directory is used in the following publications:

Kobus Barnard, Brian Funt, and Vlad Cardei, " A comparison of color constancy algorithms. Part one. Theory and experiments on synthetic data," IEEE Transactions on Image Processing, Vol. 11. No. 9, pp. 972-984, 2002.

Kobus Barnard, " Sensor Sharpening for Computational Colour Constancy ," Journal of the Optical Society of America A, Vol 18, No. 11, Nov. 2001, pp. 2728-2743.

Most experiments using synthetic data in:
Kobus Barnard, "Practical Colour Constancy," Phd thesis, Simon Fraser University, School of Computing (1999)

Data Description

Camera Sensor Data

Information on the camera sensors used for many of our experiments with synthetic data.

Illuminant data

Important: Illuminants vary greatly in brightness. The spectral data provided here is the raw data. For some applications, this data needs to be normalized.

The first set of illuminants available for download (image_data_sources) is a set of 11 sources chosen for most of our experiments with real images. The sources were:

Sylvania 50MR16Q (12VDC)---Similar to a basic tungstun bulb
Sylvania 50MR16Q (12VDC) + Roscolux 3202 filter
Solux 3500K (12VDC)--Emulation of daylight
Solux 3500K (12VDC)+Roscolux 3202---Emulation of daylight
Solux 4100K (12VDC)--Emulation of daylight
Solux 4100K (12VDC)+Roscolux 3202---Emulation of daylight
Solux 4700K (12VDC)--Emulation of daylight
Solux 4700K (12VDC)+Roscolux 3202---Emulation of daylight
Sylvania Warm White Fluorescent
Sylvania Cool White Fluorescent
Philips Ultralume Fluorescent
The second illuminant set available is a larger set of measured spectra. This set is based on a set of 81 spectra measured in and around the SFU campus, at various times of the day, and in a variety of weather conditions. Unusual lighting, such as that beside neon advertising lights, was excluded. However, care was taken to include some reflected light, provided that it was not too extreme. This set of illuminants was augmented measurements of 21 sources, including the 11 above. All these sources were all close to plausible comon illuminants. The spectra in this data set is normalized so that the maximum of each spectra is one.

To create the illuminant set used for training, we divided (r,g) space into cells 0.02 units wide, and placed the 11 illuminants described above into the appropriate cells. We then added illumination spectra from set of the measured spectra, provided that their chromaticity bins were not yet occupied. Finally, to obtain the desired density of coverage, we used random linear combinations of spectra from the two sets. This is justified because illumination is often the blending of light from two or more sources. In addition, to the extent that the diagonal model holds, these constructed illumination spectra will behave like physical sources with the same chromaticities as the constructed ones.

To produced the illuminant set for testing, we used the same procedure, but filled the space 4 times more densely.

Reflectance data

The reflectance data a set of 1995 spectra compiled from several sources. These surfaces included the 24 Macbeth colour checker patches, 1269 Munsell chips, 120 Dupont paint chips [1], 170 natural objects [1], the 350 surfaces in Krinov data set [2], and 57 additional surfaces measured by ourselves.

[1] M. J. Vrhel, R. Gershon, and L. S. Iwan, "Measurement and Analysis of Object Reflectance Spectra," COLOR Research and Application, vol. 19, pp. 4-9, 1994.
[2] E. L. Krinov, Spectral Reflectance Properties of Natural Formations: National Research Council of Canada, 1947.

The Data

The camera sensors       (gzipped).

Illuminants used for most of our experiments with real images.       (gzipped)       (info file).

Measured illuminants (normalized).       (gzipped)       (info file).

The derived set of training illuminants       (gzipped).

The derived set of testing illuminants       (gzipped).

The reflectance database       (gzipped).

Several researchers have asked for specific subsets of the above reflectance dataset. Some were measured by us, others where downloaded and converted to match the output format of the PhotoResearch PR-630 spectraphotometer (380-780nm in 4nm steps).
            1269 Munsell chips       (gzipped).
            355 Krinov reflectances       (gzipped).
            120 Dupont paint chips       (gzipped).
            170 natural objects       (gzipped)       (info file).
            7 book covers measured by ourselves       (gzipped)       (info file).
            21 samples of cardboard and construction paper       (gzipped)       (info file).
            2 more samples of cardboard and construction paper (duplicates, likely not intended)       (gzipped)       (info file).
            1 spectra of the wall of the SFU vision lab       (gzipped)       (info file).
            7 cloth samples measured by ourselves       (gzipped)       (info file).
            24 Macbeth color chart patches measured by oursevles       (gzipped)       (info file).
            19 paint-chips measured by ourselves       (gzipped)       (info file).