This paper describes and compares two color spaces – YUV and RGB, taking into account possible human-computer interaction applications. Human perception-oriented properties are compared, including not only file size or bandwidth, but also subjective visibility of artifacts. 1700 tests on a group of 170 people were performed to describe the subjective quality of compressed YUV and RGB images. Th...

PURPOSE To evaluate the association between oral low-dose contraceptives and color vision alterations. METHODS Were included in the study 30 women, sixteen used oral contraceptive for less than five years (Group I) and 14 used it for more than five years (Group II). The Ishihara, City University Color Vision Test, and the D 15 desaturated tests were used. RESULTS No characteristic alteratio...

We used Southern blot hybridization to study X chromosome-linked color vision genes encoding the apoproteins of red and green visual pigments in 134 unselected Caucasian men. One hundred and thirteen individuals (84.3%) had a normal arrangement of their color vision pigment genes. All had one red pigment gene; the number of green pigment genes ranged from one to five with a mode of two. The fre...

We used a hue-scaling task to examine changes in color perception resulting from adaptation or induction to color contrast in spatially-varying backgrounds. Observers judged the perceived color of tests after or while viewing backgrounds composed of color differences along selected axes in color space. Both contrast adaptation and contrast induction produced large and selective shifts in percei...

INTRODUCTION The relationship between visual perception and visual mental imagery are at the center of a lively theoretical debate between those postulating common neurocognitive processes between perception and imagery and those who emphasize the differences between these two entities. Neuropsychology can make an important contribution to this debate, by assessing associations and dissociation...