Brian V. Funt

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We present a study on various statistics relevant to research on color constancy. Many of these analyses could not have been done before simply because a large database for color constancy was not available. Our image database consists of approximately 11,000 images in which the RGB color of the ambient illuminant in each scene is measured. To build such a(More)
We introduce a context for testing computational color constancy, specify our approach to the implementation of a number of the leading algorithms, and report the results of three experiments using synthesized data. Experiments using synthesized data are important because the ground truth is known, possible confounds due to camera characterization and(More)
We develop sensor transformations, collectively called spectral sharpening, that convert a given set of sensor sensitivity functions into a new set that will improve the performance of any color-constancy algorithm that is based on an independent adjustment of the sensor response channels. Independent adjustment of multiplicative coefficients corresponds to(More)
We test a number of the leading computational color constancy algorithms using a comprehensive set of images. These were of 33 different scenes under 11 different sources representative of common illumination conditions. The algorithms studied include two gray world methods, a version of the Retinex method, several variants of Forsyth's gamut-mapping(More)
Many different descriptions of retinex methods of lightness computation exist. This paper provides concise MATLAB implementations of two of the spatial techniques of making pixel comparisons. The code is presented along with test results on several images and a discussion of the results. The paper also discusses the calibration of input images and the(More)
A fast color-based algorithm for recognizing colorful objects and colored textures is presented. Objects and textures are represented by just six numbers. Let r, g and b denote the 3 color bands of the image of an object (stretched out as vectors) then the color angular index comprises the 3 inter-band angles (one per pair of image vectors). The color edge(More)